12 Love, Springfieldian Style

The episode begins on a Valentine's Day afternoon. As a Valentine's Day treat, Homer takes Marge to a carnival, where they lose the kids in order to spend the day with one another in the Tunnel of Love. Inside, the two enjoy each other's company; however, Bart attempts to spoil his parents' happiness by filling the water with Jell-O, causing Homer and Marge's boat to stop. Trapped, Homer decides to pass time by telling Marge the story of Bonnie and Clyde.

In 1933, during the Great Depression, Bonnie Parker (Marge) rejects a man trying to get her attention (Cletus), saying she is looking for someone exciting. Clyde Barrow (Homer) then arrives, and after robbing a store (which he ironically co-owns with his father), the two run off. Clyde discovers Bonnie's passion is violence, and the two go on a crime spree by robbing banks. After tricking a citizen (Flanders) into helping them, the two garner intense popularity across the country. The citizen they tricked soon realizes what had happened, and snitches to the police after learning they are an unmarried couple. The Texas officers soon arrive, and the cops gun Bonnie and Clyde down. While being shot, Bonnie tells Clyde that she is looking for a man with more excitement, and that they would never have been together.

Back at the Tunnel of love, Bart and Lisa arrive at Homer and Marge's boat, and want them to tell a child-friendly story. Marge tells the story of Shady and the Vamp.

Vamp (Marge) is a royal and luxurious female dog. Shady (Homer) is in love with Vamp and eyes her from a distance, vowing that he will win her. After Shady is trampled by a mob of children, Vamp comforts him, and he asks her out for dinner. The two go to Luigi's, where, after a romantic pasta dinner (Except for the part were Shady nearly swallows Vamp over a string of spaghetti), the two run off onto a hill when the health inspector comes. In the morning, Vamp wakes up with nauseous feelings, and Shady leaves her, claiming that a fox hunter is near, knowing she is actually pregnant. In a musical number entitled "Any Minute Now" (featuring canine versions of Lenny, Carl and Barney backing up for Shady), the two dogs await for one another's return, though the cats living with a now-pregnant Vamp (Patty and Selma) convince her that Shady would never come back, whilst the dog who is friends with Shady (Moe) convinces him that he should stay with them rather than be "stuck" with Vamp and their puppies. Two of her puppies (Bart and Lisa) decide to go look for their father, and after being kidnapped by the dog catcher (Groundskeeper Willie), Shady arrives to save his children. Shady returns them home and reunites with Vamp, choosing to stay with her, but then Vamp informs Shady that there were actually nine other puppies in the litter (all of whom resemble Bart and Lisa with the exception of one, who resembles Maggie).

When Homer eventually gets bored with Marge's story, Bart tells the story of Sid and Nancy.

Nancy Spungen (Lisa), a young model student, walks into a rock concert by the Sex Pistols with her friend Milhouse, where she is enamored by the eccentric bassist, Sid Vicious (Nelson). After viewing him throw his bass at a fan at his concert, she decides to go after him. A chocolate dealer (Otto), who is in fact an undercover policeman and arrests Nancy's friend (Milhouse) shortly afterwards, sells her a chocolate bar which she gives to Sid, who soon begins dating her. As shown in a montage, the two begin having their lives spiraled out of control while gaining a chocolate addiction. Sid soon begins ditching the Sex Pistols, angering lead singer Johnny Rotten (Bart) and guitarist Steve Jones (Jimbo). Sid arrives in the middle of a performance after a major chocolate spree, and knocks into an amplifier which topples over and crushes their drummer, Paul Cook (Dolph). Nancy arrives to defend Sid, and informs the Pistols that Sid does not need them, and the two go off trying to sing a soft type of music, performing at CBGB (Comic Book Guy's Bar). When they are kicked out for playing music against everything that punk rock represents (which, according to the Comic Book Guy, is nothing), the two decide to go back to their addiction and kiss in the alley as garbage (emptied by Homer) rains down on them. Homer wishes everyone a Happy Valentine's Day and to "...shut their gobs!"