Bonnibel came from the Mother Gum and had only one brother who hit his head after being born, leaving him with a childlike behavior. She yearned to have a family and so created one to serve as such but the attempts had dire consequences and repercussions.
Neddy is Princess Bubblegum's little brother and only direct relative not created by her as shown in "Bonny & Neddy" and "Bonnibel Bubblegum". She is very protective of him, and seems to understand him well. Neddy can be calmed down by Princess Bubblegum, further showing the attachment between the two. When questioned about their radical differences, Bonnibel replies, "People get built different. We don't need to figure it out, we just need to respect it". This is a contrast to her usual scientific inquisitiveness, which really expresses her love for her infant-like brother, despite his oddities. She was also quick to defend him from the treacherous Gumbald which further showed her care for her brother.
As a child, Bonnibel was lonely and gathered supplies while for her and Neddy. While out one day, she found a mug for an uncle and decided to make herself more family members so she would others to talk to. Bonnibel then gathered the items she needed and created three other gum humanoids Aunt Lolly, Cousin Chicle and Gumbald who she made her "Uncle". They got along well but Bonnibel disagreed with his plans to make a city for Candy people and tried to counter them.
Due to her acts, Gumbald turned against her and soon did this with the other relatives as they planned to overthrow her with Gumbald's new Dum Dum Juice. Bonnibel overheard this and foiled Gumbald's plans and accidentally turned the three into simple minded candy people with the juice. She didn't change them back as they looked happy in their new forms and kept them in the dark about their identities for eight centuries. She later went through with Gumbald's plans to make a Candy Kingdom where she became its ruler.
She rarely mentioned Gumbald in the present only giving brief information about what he did for the kingdom. During “Bonnibel Bubblegum”, she tells her friends about her complicated past with Gumbald and her other family. At the end, Bubblegum becomes aware he is back since she recognized the cup BMO had got from a scientist and was worried of what will occur.
In Seventeen, she was shocked to see him and the others in their original forms and realized how they changed back. The three wanted revenge as she tried to justify her actions but they wanted to see her endure their suffering but Marceline intervened and they retreated though Gumbald swore to return after mocking Bonnibel.
In "Gumbalia", she is ready for war against her uncle and his new army and city-state Gumbaldia. Finn and Jake wanted to call off the war and went to confront Gumbald on the matter. They were seemingly successful with Gumbald calling off all hostilities with his niece and splashed Finn and Jake with "celebration juice" with Gumbald telling the two to give Bonnie a big hug. PB was happy to have a signed by peace treaty and was about to hug Finn, but noticed the smell of the juice. Peppermint Butler went to wipe the juice off only to become a baby-like peppermint seconds later. Bonnie then realized that the juice was Dum Dum Juice and her uncle had attempted to have subjected to it. Furious, Bubblegum officially declared war on her uncle.
In the series finale "Come Along With Me" Princess Bubblegum was still furious on the verge of war with her uncle. Finn was still unhappy and asked Bonnie to call off the war again. PB agreed to give Gumbald one more chance. The confrontation between Bonnie and her uncle was ugly. Finn and Jake then splashed themselves, PB, Gumbald and Fern with nightmare juice forcing them into hallucianry slumber. Finn did it with the hopes of them learning to get along, thus calling off the war.
Inside the dream realm, PB and Gumbald continue to be hostile towards each other. Gumbald leaves the area and despite Finn's protest, Bonnibel decides to pursue him. PB and Gumbald later recreate a nightmare version of the moment that PB defeated Gumbald by dousing him with his own dum-dum juice, only this time with the roles reversed. PB is doused, and is transformed into a smaller, less intelligent version of hersel, while Gumbald was placed in the life of his niece, being very stressed and paranoid about the safety of the Candy Kingdom. Gumbald and PB are later brought to tears after both witness the Candy Kingdom turn into a pile of goo in the dream.
After the four of them wake up from their dream, PB apologizes to Gumbald for not respecting his vision for the Candy Kingdom. Gumbald fake-accepts her apology and agrees to end the conflict, intending to betray her, but is tripped by Aunt Lolly and once again doused in his own dum-dum solution, turning back into Punch Bowl and officially cancelling the war.
Bonnibel created her as a way of having a family and made Lolly her aunt. At first, they got along but Gumbald turned Lolly against Bonnibel as they planned to overthrow her and Lolly even laughed at Chicle's remark of Bonnibel, leaving the latter sad. However, Bonnibel foiled Gumbald's plans and accidentally turned the three into simple minded candy people. She didn't change them back as they looked happy and kept them in the dark about their identities for eight centuries.
It appears she retains her love for Lolly as she keeps portraits of the of them together, as seen in The Duke.
In Seventeen, she was shocked to see her and the others in their original forms and realized how they changed back. The three wanted revenge as she tried to justify her actions but they wanted to see her endure their suffering but Marceline intervened and they retreated.
In the series finale "Come Along With Me", Finn and Jake put Princess Bubblegum and Gumbald together in a nightmare, convincing them to make peace with each other and call off the war. PB forgave Gumbald, however, as the latter pretended to forgive her, he was going to splash her with his Dum Dum Juice, but Lolly tripped him and he was splashed with it, becoming the Punch Bowl again. Lolly then forgave her niece and called off the war making piece with Gumbaldia, though GOLB arrived only moments later. Lolly contributed to the fight against GOLB, leading the Gumbaldian cake soldiers and telling them to set aside past differences with the Candy Kingdom.
Bonnie and Lolly seem to have really reconciled, as the two were later seen bonding together, singing lullaby to Neddy.
Bonnibel created him as a way of having a family and made Chicle her cousin. At first, they appeared to have gotten along fine with Chicle giving her the nickname "BB" but Gumbald turned Chicle against Bonnibel as they planned to overthrow her. Chicle even voiced his distaste for her being leader as he described her talks "like that of a mime" as he never heard what she said. An eavesdropping Bonnibel was hurt by these cold words. However, she foiled Gumbald's plans and accidentally turned the three into simple minded candy people. She didn't change them back as they looked happy and kept them in the dark about their identities for eight centuries.
In Seventeen, she was shocked to see Chicle and the others in their original forms and realized how they changed back. The three wanted revenge as she tried to justify her actions but they wanted to see her endure their suffering but Marceline intervened and they retreated.
The Earl of Lemongrab
Princess Bubblegum created The Earl of Lemongrab for the purpose of ruling the kingdom if she ever became unable to do so. However, being the first of her "experiments gone wrong," her creation is exceedingly temperamental and a terribly inexperienced ruler. Princess Bubblegum and the Earl of Lemongrab initially dislike each other, and Princess Bubblegum calls the Earl a "butt." According to Princess Bubblegum, "it's complicated." While in power, Lemongrab is intent on sending everyone, including Princess Bubblegum, to the dungeon for conflicting with his rigid agenda. However, when the Princess returns to the age of 18, she fires the Earl by shouting "Yo, Earl! Hey! You're fired, ya butt!" Princess Bubblegum is treated with the same rudeness, obnoxiousness, and sense of entitlement as Lemongrab treats everyone else. Although he does think of her as his creator, he also blames her for the difficulties in his life.
In "You Made Me," Princess Bubblegum is much kinder to Lemongrab when he articulates that he is lonely. This might be because she understands what causes his attitude and behavior. He refers to her as "his glob," which might mean that he acknowledges that she is his creator, similar to how a god creates something in religion. Although he is hostile and threatening towards her, and reacts with fear, she continues to help him and speak to him in a gentle, coaxing manner, and eventually makes him a Lemongrab clone to be his friend. By the end of the episode, the two Lemongrabs and Princess Bubblegum are on good terms. Princess Bubblegum says "Take care, boys!" to them, and they respond by requesting she visit them.
In "Mystery Dungeon," Lemongrab cries out "MOMMY!" as he has the life-juices squeezed out of him, in reference to Princess Bubblegum, indicating that he does see her as a parental figure. In "All Your Fault," the Lemongrabs refer to her as "Mother Princess" and "family." In the episode, she sees them as a frustrating nuisance, but is still willing to be kind to them and help them when they are in a tough situation. In All Your Fault, Lemongrab screams "You're my glob!" to Princess Bubblegum referring to her as his creator. When Jake calls the Lemongrabs "selfish," Princess Bubblegum says, "Oh, no. Their hearts are fine. They're just like this," and they smile. In "Too Old," Princess Bubblegum shows concern and looks shocked when Lemongrab appears in front of her, and during dinner, she commented on how different he and Lemongrab 2 were.
Bubblegum created Lemongrab 2 to be with the Earl of Lemongrab in the episode "You Made Me." She created him just like she did the Earl of Lemongrab, and made them identical in appearance. Just like with the Earl of Lemongrab, Princess Bubblegum is like Lemongrab 2's mother.
In "Too Old," she is surprised in the differences between the Earl and Lemongrab 2, with the Earl being very large and fat, and Lemongrab 2 having no legs, a large bite mark on his head, and relies on a hovering device to move. This is a result of what happened in "Another Five More Short Graybles."
Lady Rainicorn is Princess Bubblegum's best friend and trusty steed. Lady Rainicorn is one of four creatures she uses for transportation; the others are her swan, Jelly Horse, and the Morrow. She and Princess Bubblegum appear to be very close, similar to Finn and Jake. Princess Bubblegum understands Korean (Lady Rainicorn's first language), though she has not been heard speaking it in the series, conversing in English to Lady Rainicorn in "Video Makers" and "Lady & Peebles." In "Lady & Peebles," Princess Bubblegum shows to be completely loyal to Lady Rainicorn, refusing to give up on her, even when she was injured. It is also the case that Princess Bubblegum was the first to find out that Lady Rainicorn was pregnant.
Princess Bubblegum and Jake have a rather strange relationship, with Jake being well aware of Finn's former crush on her. Despite this, they seem to maintain a healthy friendship with Princess Bubblegum, even calling Jake "puppy" and allowing him to rest his head on her lap in "Incendium." It was revealed in "Mortal Recoil" by Jake that Princess Bubblegum likes it when Jake plays songs.
Even though they are good friends, in "Princess Cookie," Princess Bubblegum wanted her guards to arrest Jake after he helped Baby-Snaps, and in that same episode Jake pretended he hated her because she made him be a milkman instead of a mailman, as he went undercover to stop Baby-Snaps.
In "Burning Low," Princess Bubblegum seemed content to speak with Jake about the possibility of Finn having a girlfriend. When Jake becomes under the impression that Princess Bubblegum is jealous, he becomes angry with her for hurting Finn and threw a box at her, saying "You're sick!" However, when the princess clears up the misunderstanding, Jake is more than willing to help. At the end of the episode, Jake teases Princess Bubblegum by calling her "jealous," to which she responds with a deadpan "Shut up."
In "A Glitch is a Glitch," Princess Bubblegum makes a hand face with bumps on the side of her palm which she uses to kiss Jake's similarly morphed elbow with. This was likely a gag, as the episode is separate from the continuity of the rest of the series.
In "Too Old," Princess Bubblegum tells Finn that it was a shame Jake did not come because she loves him.
Lumpy Space Princess
Lumpy Space Princess is one of Princess Bubblegum's best friends. Despite their drastically different personalities, the two are often together and Lumpy Space Princess is a frequent visitor to the Candy Kingdom during many of its parties and ceremonies. Their relationship can also be seen having tension, as in "Bad Timing", when Lumpy Space Princess called Princess Bubblegum a "pretty skunk" and began tearing out her hair, pushing Bubblegum to the point of suggesting war between the Candy Kingdom and Lumpy Space. Despite this, she still assists LSP in helping her forget the heartache of her short-lived boyfriend by sending her back in time to before she encountered him.
Princess Bubblegum and Shoko grew close in the episode "The Vault." Shoko originally only befriended Princess Bubblegum because she wanted to gain her trust so that she could steal the amulet. However, after the princess gifted Shoko with an artificial arm to replace the one she lost, the thief began to regret having to steal from her new friend. Knowing that the penalty was death if she failed to steal the amulet, Shoko went ahead and tried to take it while PB was sleeping, but was busted by Gumball Guardians. At the end of the episode, Shoko has the amulet returned to PB (via Finn), and there seem to be no hostile feelings between the two.
Princess Bubblegum loves all of her candy citizens. However, Cinnamon Bun seems to be unlike any of the others to her. He seems to be slightly ignorant to even the simplest of tasks, but Princess Bubblegum still seems to respect the odd ways in which he lives his life. She even allows him to keep a fake pet in "Earth & Water," and allows him to have a real one later on in the episode. She seems quite stern, even motherly, when necessary, though. However, the two always seem to make up and are back to normal in the end.
He was one of her Gumball Guard but she had them disassembled once they proved to be dangerous. Rattleballs developed freewill and escaped by hiding out in the dump ever since. Bubblegum was unaware until Finn informed her of this and she sent the Banana guard after him to execute him. Rattleballs fought her guards but showed them mercy, he surrendered while stating he still follows Bubblegum and accepted his impending fate. However, she was moved by his compassion and faked his death, while charging him with defending the kingdom in secret, something he accepted. Before he could leave, she bestowed upon him the title of Sir Rattleballs and a new sword for his position.
At the start of the series, Princess Bubblegum was Finn's love interest. However, it was unclear if these feelings were mutual. She often rolled her eyes at his advances, but at other times seemed genuinely flattered, kissing him numerous times from the animated short to "Wizard Battle". Princess Bubblegum cites Finn as a great friend, never hesitating to seek his aid in royal matters, calling him as "my hero" on several occasions. Finn and Princess Bubblegum share the same moralistic nature and often work together to right any wrongs in the Land of Ooo.
Finn has a few nicknames for her, such as PB, Princess, Bubblegum, Probbles, Preebos, P-bubs, Prubs, and Peebles.
In "Slumber Party Panic" she called Finn "adorable." The princess also sees Finn as her "flawless champion," as said in "The Duke." It is also shown that there is a picture of Finn on her wall. In the same episode Princess Bubblegum reveals she could never hold a grudge against Finn. In "To Cut a Woman's Hair," she says explicitly that she likes Finn, although she could have meant platonically or maternally. In "The Real You," she gives Finn a kiss on the cheek for saving the Candy Kingdom from the black hole he created and making her Science Barbecue a huge success. In "Go With Me," she exiles Finn from the Candy Kingdom after he releases a pack of wolves into her room, but her anger proves temporary as Princess Bubblegum appears to have forgiven Finn by her next appearance.
In "Mortal Folly" she told Finn "I care about you," then giving him a pink sweater with a white heart stitch to the left that she made with the power of "liking someone a lot." This proved essential in helping Finn defeat the Lich. At the end of "Mortal Recoil," Princess Bubblegum ages down to 13, which led to the events of "Too Young."
In the episode, Princess Bubblegum acts very loving and affectionate toward Finn during the time she is 13, even going on a "date" with him, leaning on his shoulder, and holding his hand. Finn's former feelings for her appear reciprocated while she was 13, and this may indicate Bubblegum's true feelings for him have always been of love, or this might only apply when they are the same age. She expresses some regret when she has to turn back to 18 because she never gets to "act like a kid." She also says to Finn that she would rather "stay like this, with you." During her transformation back to 18, they share a hug and she kisses Finn on the lips. When she has changed back to 18, she returns to her usual personality, no longer demonstrating romantic affection for Finn. When Finn asks whether they could "hug some more," she replies by saying "That was like 5 years ago... You really gotta move on!" She makes this remark with a smile and then mutters "Such a silly boy" as she walks back into the castle.
In "Wizard Battle," she forgives Finn for cheating in the contest, then they share a quick kiss on the lips (their final real kiss together), after which she slaps him on the cheek for cheating.
In "What Was Missing," it was revealed that Finn keeps the clump of Princess Bubblegum's hair that he got in "To Cut A Woman's Hair" as a prized possession. It was also seen in "Incendium" while Finn was singing "All Gummed Up Inside" and again when he saves Flame Princess from falling.
In "Incendium," Jake says that Princess Bubblegum is too old for him. This age gap might also be the only reason she keeps pushing him away, as when she turned thirteen she showed romantic affection to Finn.
In "In Your Footsteps," Jake refers to Princess Bubblegum as Finn's "ex-girlfriend," to which Finn responds "She's not my... We never went steady."
In "Burning Low," Princess Bubblegum becomes pleasantly interested when the news comes up that Finn is hanging out with another girl, but then she acts distraught when she finds out Finn has been hanging with Flame Princess. She attempts to explain to Finn and Jake why he should not date her through complicated scientific facts, though Finn leaves to meet Flame Princess and Jake falls asleep. Jake comes to the conclusion that Princess Bubblegum is jealous of Flame Princess and shares this with Finn. She confronts Finn the next day and attempts to console him, believing that he knew about the situation. However, when she starts talking about responsibility demanding sacrifice, Finn misinterprets this as her displaying jealousy for his relationship and shouts to her about his past feelings towards her. Princess Bubblegum finally tells Jake that she was the one who had Flame Princess locked up so she does not fall in love and destroy the Earth from the inside.
Princess Bubblegum's advice to Finn that "responsibility demands sacrifice," indicates that sometimes, when one loves someone enough to kiss them, one may have to sacrifice the chance to do so because the greater good demands that they refrain. She intended for Finn to apply this to his desire to kiss Flame Princess, which could cause the destruction of the planet. However, he interprets it incorrectly, believing that Princess Bubblegum is referring to her own royal responsibilities preventing her from kissing him. She doesn't seem to mind Finn having a relationship with Flame Princess, although she says that she feels sorry for both of them. However, Jake sees it as a sign of a jealousy, to which she quickly tells him to "shut up."
In "Lady & Peebles" she struggles to find Finn and Jake, finds out that they were both captured by Ricardio, saves them and treats them back in the Candy Kingdom.
In "Reign of Gunters," although Finn says he is over Princess Bubblegum, he takes the advice of a dating book called Mind Games and tries to act more mysterious. He claims he needs to keep all the ladies in a state of confusion; that way, he has "options in case Flame Princess doesn't work out."
In "The Lich," Princess Bubblegum becomes angered when Finn tries to take her royal gem from her crown and starts struggling to push him away, causing her to accidentally cut him on the cheek with scissors. Finn staggers backwards and hisses in pain, glaring angrily at the Princess before taking the gem from the fallen crown and leaving through the roof with Jake despite Princess Bubblegum's calls and her saying that it was an accident. However, subsequent episodes indicate that they are on friendly terms again.
In "Too Old," after Flame Princess breaks up with Finn over the events of "Frost & Fire," he tries to rekindle romance with Princess Bubblegum, who rebukes him, saying: "Finn, I have citizens who need me. I can't always treat everything like a little boy game." At the end of the episode, Finn realizes that "maybe age isn't just a number. Maybe older people, like, really are different.... I think I really sponked up."
In "Rattleballs," Finn tries to get over his relationship with Flame Princess by protecting and serving Bubblegum, and takes to annoy her first thing in the morning in Ice King fashion. Bubblegum is annoyed with him and tries to ignore him. When she needs milk, Finn overdoes it and spends three weeks getting a tiny vial of mink's milk, which Bubblegum rejects. Finn also serves her "one hundred percent," like how the Gumball Guards were programmed to. Although it is unknown if he is interested in Bubblegum again, he seemed to overdoes the task and wants to be her servant.
At the end of "Breezy," the duet song "Love" between Finn and Breezy shows Breezy replaced by a vision of Bubblegum, who also takes part in the duet. This suggests Finn's romantic interest in her may be reawakening.
This is later seen in "The Pajama War" where Princess Bubblegum wants to just casually hang out with Finn. They somewhat flirt with one another and make it work despite the age difference. It is unknown if PB now has romantic feelings towards Finn.
In the series finale "Come Along With Me", after the defeat of GOLB, PB came to what remained of Finn and Jake's house to thank them. She kissed Finn on the cheek but this was not exactly in a romantic way and Finn had a mature and mellow response. However she does acknowledge that he is getting tall, a possible sign of her romantically warming up to him with him maturing, but there is no real evidnece of that.
In the original pitch documents, Princess Bubblegum and Marceline are shown to be friendly rivals. Though appearing at the same place at the same time on several occasions, the nature of their relationship was not known until "Go With Me," where we see Marceline mockingly greeting Princess Bubblegum, much to her displeasure. Marceline is the first and only character to call Princess Bubblegum by her first name (Bonnibel) and usually shortens it to Bonnie. Similarly, in "Sky Witch," Princess Bubblegum shortens Marceline's name to 'Marcy.'
Marceline appears to view Princess Bubblegum as boring and a snob, while Princess Bubblegum, generally a woman of grace and poise, views her as unrefined and rude. In "What Was Missing," when Princess Bubblegum miscalculates the music needed to open the door, Marceline says, "Looks like you aren't as perfect as you thought! Guess you can't judge me anymore." Princess Bubblegum angrily replies, "I never said you had to be perfect!" hinting that the relationship between the two had had ended on bad terms. However, in the same episode it is revealed that the item stolen from Princess Bubblegum was a t-shirt Marceline had given her, which she confesses she values deeply and wears it as pajamas, showing she still cared for her old friend.
In the episode "Sky Witch," Princess Bubblegum is shown sleeping in the shirt that Marceline gave her, and, when she wakes up, she smells the shirt deeply, before wearing it under her clothes. A picture of Bubblegum and Marceline is also shown hanging in Bubblegum's closet. As it is not clear when this picture was taken, it could have been taken during their close relationship or more recently when they have since gotten close again. Later on in the episode, Marceline visits Princess Bubblegum at the castle, pushing a Gumball Guardian out of the way, entering the windows, and closing the curtains without the Guardian complaining or otherwise reacting at all. Initially, Princess Bubblegum tries to act busy, but when Marceline expresses that she wants the Princess's help to find Maja the Sky Witch, Bubblegum agrees to help her. When trying to get her to relax through Maja's bramble barrier, Bubblegum calls her 'friend,' smiles, and gives her tea. However, the Princess is annoyed to discover that Marceline is simply looking for her old toy, Hambo. She attempts to dissuade her, saying that Raggedy Princess could make her a new Hambo "or be [her] new Hambo," but, after realizing how much Hambo truly means to Marceline, she agrees to continue helping her search for it despite how dangerous it may be.
Eventually, Princess Bubblegum barters for Hambo by offering Maja the T-shirt that Marceline gave her, an object that Maja notes has "sentimental freshness" and "psychic resonance" greater than Hambo's. Bubblegum chooses not to tell Marceline how she got Hambo back, stating only "I took care of it," and climbs onto Marceline's back so they can fly out of Maja's home.
Princess Bubblegum and Marceline's friendship is further explored in the comic Adventure Time: Marceline and the Scream Queens Issue 1, in which Bubblegum becomes the manager of Marceline's band. However, the comics are not considered canon to the series.
In the episode "Varmints," Bonnibel and Marceline's past relatonship is brought up again. Also, at the beginning of the episode Marceline is frustrated to find out that Bonnibel lost her princess-ship. She also seems angry when she asks where Bonnibel went. It is revealed that their relationship was strained because Bonnibel had to manage the Candy Kingdom. She said, "The Candy Kingdom used to be so small, so manageable; then it kept growing and growing, and there was always some new disaster to prepare against." Then Marceline responds with "Is that why you stopped talking to me?" Bonnibel replies, "No, I-". She then gets cut off by the sound of a mother Varmint.
Bonnibel calls Marceline "Marcy" again in this episode. This happens when Marceline gets knocked out, and Bonnie drags her away. At the end of the episode Marceline ends up watching Bonnibel's farm for the night, which Bubblegum sleeps on her shoulder.
In "Take Her Back" Bonnibel says, "Now my best friend is dying of poison because of me." In this sentence she was referring to Marceline. Later in "Take Her Back," when the Moon breaks into the safe, Bonnibel starts crying and pleading to Marceline to wake up from her "poison coma." In "Checkmate", when Marceline is doing "bat jacks" (jumping jacks) with Bonnibel, she describes a weird feeling in her stomach. Bonnibel suggests that it is fear, but then Marceline tells her she knows it isn't fear. Marceline then says, "Maybe its love?" Then Marceline's stomach starts to grumble. Jake arrives with snacks. Jake and Marceline are happy to have the food. Jake says, "I love you Bonnibel!" as he stuffs his mouth with a burger, and Marcenline says, "Me too Bonnibel!" as she stuffs her mouth with a sandwich.
At the end "The Dark Cloud," Marceline thanks Bonnibel for helping her mature. She then says, "Now I guess we get to hang out with each other forever," which causes Bonnibel to blush.During "Seventeen," when Bonnibel's relatives appear for revenge but Marceline quickly intervened showing concern for her friend.
In the series finale, "Come Along With Me ", Marceline sees Bonnibel get crushed by an enemy. Enraged, she attacks it and manages to hold it off. When it turns out that Bubblegum is all right, Marceline rushes to her side and expresses relief and concern over her and after a tender moment, the two affirm that they care for one another and after Bonnibel reassures to her that she will be fine, the two kiss.
Later, in the montage at the end of the episode, the two are at Marcy's house seen cuddling beside each other on a couch enjoying their happy lives together as a couple.
Ricardio seemed to have common interests as Bubblegum and they became friends very quickly. They are seen dancing together and preparing to perform scientific experiments. However, at the end of the episode "Ricardio the Heart Guy," it is revealed that Ricardio is Ice King's sentient heart who wishes to bring Bubblegum's heart to life and marry it. Princess Bubblegum was kidnapped and held hostage by Ricardio. However, he was beaten up by Finn and Jake and was returned back into Ice King's body.
The two meet again in "Lady & Peebles," where Ricardio escapes, builds himself a body out of Ice King's flesh and poisons Finn and Jake to lure Bubblegum into a Black ice cave in the Ice Kingdom. When she finally came, he reveals that this time he wants to marry Bubblegum herself. She then finds that Ricardio's limbs were weakly attached and challenges him to a fight and then tears them apart. She leaves him in a bad condition, as he says he only wanted to impress her but she angrily says that he failed and warns him to never come back as weakly limps away.
Duke of Nuts
Princess Bubblegum is shown to have an outright hatred for the Duke of Nuts because he eats all of the Royal Pudding. In the episode "The Duke," he explains to the princess that it is due to a medical condition; his pudding deficiency causes him to lose control and eat all of the pudding. Princess Bubblegum tells him that all is forgiven, but reveals to Finn that she still does not trust the duke.
King of Ooo
Princess Bubblegum has shown some resentment towards the King of Ooo and believes him to be a fraud. She does not accept his authority as a king and dislikes him. Trying to prove that he was a con man, Bubblegum breaks into his blimp to search for proofs. She finds an expired certificate stating his right as a priest for Tree Trunks's wedding and tries to use this as a reason to arrest him. However, she was proven wrong by the King of Ooo and was accused for snooping and breaking into his blimp. Not willing to admit that she was wrong, Bubblegum sends him to jail unfairly when he was not at fault, as well as the other wedding guests when they protest.
Ice King spends a great deal of his time obsessing over capturing princesses. His most targeted princess is Bubblegum, who is annoyed with the Ice King's actions but generally seems to put up with them. One of the few times that Bubblegum shows particular anger towards Ice King is in the episode "What Have You Done?" When Ice King's attempt at a kind gesture (making it snow) ends up making nearly the entire kingdom sick. When the Ice King selfishly neglects to acknowledge Princess Bubblegum's purpose in asking him to help, she becomes frustrated with him, ultimately forcing Princess Bubblegum to order Finn and Jake to capture the Ice King at all costs without telling them why she wants him imprisoned.
In "Mortal Folly," Ice King's obsession with Bubblegum nearly leads to the destruction of Ooo. As Finn is fighting the Lich, the Ice King captures her, intending to marry her. After the Lich is defeated, Ice King accidentally drops the princess into the Lich's evil power source, corrupting her. However, he is still loyal enough towards her to help save her life after her broken body was possessed by the Lich to destroy Ooo.
Regardless of Princess Bubblegum's feelings on the situation, the Ice King really does care for her. Ice King cries hysterically when she is hospitalized in the episode. By the end of "Mortal Recoil," Ice King becomes uninterested in her when she became underage. Once Princess Bubblegum is revealed to have turned thirteen, he says, "Ah, dang it! Well, I'm out of here. Goodbye, everyone!" and leaves through the window. Since her return to the age of 18, he is once again interested, as seen in "Wizard Battle."
Despite the awkward nature of their relationship, they are capable of being civil and even hanging out. This is shown in the ending of "Holly Jolly Secrets Part II" when the Ice King and Princess Bubblegum sat next to each other drinking hot cocoa. Although the Ice King was annoyed by Princess Bubblegum also being close to Finn, she did not seem to mind the Ice King being so near her. This indicates that perhaps he has learned some restraint, and Princess Bubblegum does not dislike his company as much as she used to.
She likely still strongly dislikes the Ice King after he stole part of her head in "Princess Monster Wife." However, she describes the Ice King, in "Lady & Peebles," as not usually being "a serious threat." She saves the Ice King at the end of the episode, giving him a new heart after she defeated Ricardio. She did not appear to show malice towards him, and said "please" before asking him to stop being annoying and to leave.
In "A Glitch is a Glitch," Ice King "reminds" Princess Bubblegum about how she had told him that she would go on a date with him if he was that last person in Ooo, but she replies by saying that she doubted that she really said that. Later, she tells the Ice King that even if she actually said that, he still would not be the only person in Ooo because she is still there and starts making out with her own hand, showing she would rather be in love with herself than with Ice King and that she still has a strong distaste for him. However, this episode is considered non-canon with the series.
In "Princess Potluck," she invited him to the Princess Potluck, but Ice King did not know, because he never read the invite. Usually it was traditional that she never would include the ice king to any parties or ceremonies.
The Ice King officially gives up on Princess Bubblegum in "The Party's Over, Isla de Señorita." When he tried to kidnap Princess Bubblegum again, Ice King realized, based on her reactions, that she did not actually love him, and traveled far out to Ooo to start somewhere "fresh." Ice King describes to the Island Lady his relationship with Princess Bubblegum, though there actually is none, and connected with her relationship with the Party God through this. Ice King goes far as being irritated at her at the end of the episode, something which has not happened before in the series.
After the events of "Broke His Crown" (where Marceline forces her to spend time with her and Ice King) she seems to have forgiven Simon for the kidnapping and hitting on her in the past. This is seen in "Don't Look" when she tells Finn and Jake to do something about his presence. However she does state that he's been good lately. In "The Music Hole" she even had him be the security guard for the Battle of the Bands.
In "Burning Low," Princess Bubblegum reveals that she was responsible for Flame King imprisoning his daughter, Flame Princess, in a lantern. Bubblegum knows in great detail about her physical instability (if she were to experience extreme romance she could cause a catastrophic meltdown of the planet) and tries to stop Finn from kissing her, but fails. Princess Bubblegum seems to be okay with Finn having a relationship with her, although she feels sorry for them both.
In "Earth & Water," she was "observing" Flame Princess's elemental matrix. She explains to Flame Princess that she was a threat, and that if she could create a scientific model that described her complete elemental matrix, she could isolate and suppress her violent feelings, which Flame Princess agrees to. A past connection of her with the Flame Princess is also shown; when she was a baby, Flame King attempts to abandon her in the woods, but she ends up running into the forest and caused a destruction. Princess Bubblegum sees this and returns her to the Fire Kingdom. She told the Flame King about the destruction and advised him to lock her up into a lantern. When she discovered that Flame Princess had became the new ruler of the Fire Kingdom and that Cinnamon Bun was with her, she attempts to get him back. However, after Cinnamon Bun protests, she accepts it and leaves him as her right man.
In "The Cooler" the fire kingdom is in an unusual cold season. Flame Princess said they needed Princess Bubblegum as an ally to solve this. Princess Bubblegum knew the Sleeping Fire Giants were a threat to the Candy Kingdom so she sabotaged them. Throughout the episode Flame Princess showed minor hatred towards PB. It is later revealed that she's been spying on them with a camera hidden in Cinnamon Bun and she (along with Ice King) are responsible for the cold season. PB apologizes and says she doesn't want to be seen as a bad person. It is revealed at the end she has been spying on many people and breaks all the cords shutting all of them down. Due to shutting her cameras down she is seen to now be way more "chill" than used to be as seen in "The Pajama War."
In "The Suitor," Princess Bubblegum meets one of her many admirers, Braco. However, she refuses to date him (or spend any time with him, aside from experimental purposes), explaining that he only had an infatuation with her. Princess Bubblegum invents a robot copy of herself, P-bot, to act as his wife. Braco tells her that it feels wrong, but P-bot kisses him and, satisfied with P-bot, Braco takes her and thanks Princess Bubblegum before jumping out of the window with his new wife. Princess Bubblegum then stares at them as they leave and quietly says "You're welcome, my love." However, it is unknown if she said it out of true emotion or due to the spell placed on Ogdoad.
In "Mortal Recoil," Raggedy Princess is one of the guests in Princess Bubblegum's hospital room, showing that she cares about the princess's well-being. However, in "Sky Witch" Princess Bubblegum expresses distaste for Raggedy Princess's general behavior, saying that Raggedy Princess has "zero self-respect." In the same episode, Princess Bubblegum acknowledges Raggedy Princess's sewing talent and seems impressed and sure of herself when she describes it to Marceline although she has no relationship to her really.