Slime Princess needs a husband or else she'll lose the Slime Kingdom to her hot and obnoxious sister. Finn steps in to save the day, but first they will need to win a series of Love Games to prove to Elder Plops that they are really in love.
Finn and Jake are hosting what appears to be a talk show (with Finn claiming that he no longer wants to date anymore) when Slime Princess arrives and announces that she needs help with an emergency. Finn is eager to help until Slime Princess says that she needs Finn to marry her or else she will lose the Slime Kingdom. Finn states that he is unable to do so, and Ice King interrupts and volunteers himself as husband before Jake tells him off.
Slime Princess explains that her sister Blargetha recently married a slime rogue named Guillermo, leading the elder of the Slime Kingdom, Elder Plops, to decree that rule over the Slime Kingdom will be passed to Blargetha unless Slime Princess marries the next day. Slime Princess says that this would not normally be a problem, but she discovered that Blargetha and Guillermo are evil and plan to conquer the Ooo. Finn refuses anyway and only hesitantly accepts when Slime Princess says that the marriage would be in name only.
Arriving at the Slime Kingdom, a wasteland "oasis" of slime, Slime Princess leads Finn and Jake to the "most important place" in the Kingdom, a discotheque where Slime Princess and all her "main splurts" hang out.
While introducing Finn as her new husband to the Slime Kingdom's citizens, Slime Princess's sister Blargetha arrives with her husband Guillermo. Claiming that Guillermo is unable to do so himself due to a severely sore throat, Blargetha challenges Finn and Slime Princess to the Trials of Glarb, a series of love games. Slime Princess objects to this; however, Elder Plops agrees, saying that whichever couple he deems to be "the most truly in love" will rule the Slime Kingdom.
The first trial is crooning, in which the contestants climb into a Slime Swan Boat and sing a song, and Elder Plops judges the winner. Finn is still troubled by his relationship issues, but Slime Princess encourages him to simply let his emotions out. They win the first challenge with Finn's song about his inability to get over Flame Princess. They lose the second challenge, however, when Finn refuses to spoon with Slime Princess, and Blargetha ties the scores. Elder Plops announces that the final trial, smooching, would be held the next day.
Later, while unsuccessfully trying to practice for the smooching trial, Finn decides to just punch Guillermo until he agrees to leave the kingdom. They arrive at Blargetha's room, and he calls for Guillermo to come out, but Blargetha angrily responds instead. Breaking into the room, they follow Blargetha down a set of stairs and find a chamber filled with Slime Tanks. Blargetha fires at them from one, but they manage to dodge and climb inside where Finn punches Guillermo, only to discover that he is actually just a blob of Slime with olives for eyes that Blargetha made. Blargetha explains it is not easy being as attractive as she is. Finn wants to send her to prison; however, Slime Princess says that Blargetha is simply disqualified.
Elder Plops announces that Slime Princess is still the ruler of the Slime Kingdom, and the citizens call for Slime Princess and Finn to kiss. Slime Princess asks him what he thinks and Finn, not wanting to disappoint the people, willingly prepares to kiss Slime Princess when suddenly she turns away to vomit, saying that she cannot do it. Elder Plops frowns.
- Slime Guards
- Slime Warriors
- Ice King
- Tree Trunks
- Mr. Pig
- Flame Princess (mentioned and pictured)
- The song "I Just Can't Get Over You" is about Flame Princess.
- The bunker-like room which Blargetha and Guillermo appear in Slime Princess' story has posters similar to German Propaganda posters of World War II. One of the most notable is the middle poster, which contains a cartoon of a Slime Person with many warplanes on it. The poster is similar to Nazi dictator Adolf Hitler's propaganda poster, which hung in the streets of Berlin in 1944-1945.
- The military weaponry and arsenals owned by the Slime Kingdom resemble German tanks and warplanes. The fleet of planes resembles the famous Messerschmitt WWII Warplanes and the tanks resemble those of a Panzer III tanks used by German Military in the 1940s.
- Jake's comment on Slime Princess' oasis may be a reference to the band of the same name (Oasis) and its tribute band, No Way Sis.
- The title card from this episode is similar to the one from "Slime Central."
- Ice King still lives with Finn and Jake, a result of the events in "Frost & Fire." He moves in with them in "Earth & Water." Strangely, he does not appear in "Time Sandwich" or "The Vault."
- Finn is still not over his breakup with Flame Princess in "Frost & Fire."
- Slime Princess said she knows she had crushed on Finn in the past. This may be a reference to the episode "Prisoners of Love" where she said she would like to marry Finn.
- Slime Princess's disgust when trying to kiss Finn may also be a reference to "Prisoners of Love," as she may still believe that he pees his pants.
- Elder Plops refers to tomorrow as "on the morrow." In "Death In Bloom," Finn thought that when Princess Bubblegum said "on the morrow," she was referring to tomorrow.
- This is the first episode storyboarded by Andy Ristaino.