The first segment is a retelling of Bonnie and Clyde, and the characters in the cartoon of the segment are parodies of Woody Woodpecker and Speedy Gonzales, which Chief Wiggum finds racist (a reference to how modern audiences feel about ethnic cartoon characters, such as Speedy Gonzales).
The second segment of the episode is a parody of Lady and the Tramp. The dog that was taken into the gas chamber in the segment is a parody of Disney's character Goofy.
Coincidentally, one of the proposed names for Tramp was "Homer".
The third segment is a reference to the romance of Sid Vicious and Nancy Spungen and the film Sid and Nancy. Bart is also featured in the story as Johnny Rotten, and the 1987 film Sid and Nancy which depicted said romance. The plot has chocolate substituting drugs, which is similar to "The Regina Monologues". CBGB was a music bar (though it is discovered that the abbreviation stands for Comic Book Guy's Bar; in real life it stood for "Country, BlueGrass, and Blues" despite the venue's association with Punk Rock).
Ironically, the first and third real love stories in this episode end tragically. Bonnie and Clyde were ambushed in 1934, as shown in the episode, and in real life Nancy Spungen died of a stab wound in 1978, with Sid Vicious charged for her murder, pleading innocent and after multiple suicide attempts, dying of a heroin overdose in 1979 just after making bail and completing a detox program.
Despite Bart insisting it was dark, the unpleasantness of the real Sid/Nancy romance was definitely eased up on for the audience and there was nothing romantic about it at all. It consisted of a lot of fighting, a lot of make-up sex, a lot of drugs, a lot of drug-sex, and Nancy convincing Sid to enter a suicide pact, and was destined to end in tragedy.
Nancy was never a model student. She was actually a rebellious teenager who ran away from home and moved to New York. She was already doing heroin when she met Sid at a show, and Sid had his own alcohol and heroin problems even before he met her.
Paul Cook (played by Dolph) refers to Sid Vicious as Sidney Sheldon Vicious, but his real name was John Simon Ritchie.
This is the first episode in a row where a character (Bart/Nancy) orders another character to do something (Skinner to go knitting/Sid to bang his head against a wall) and they obey, claiming that they are only doing it because they want to.
This is the second episode to air in the UK after the Watershed hour (the first was Weekend at Burnsie's) due to adult content.
The Channel 4 airing of this episode had major edits; the Bonnie and Clyde part ended as the police fire at the car, the scene where the Goofy-like character enters the gas chamber in Shady and the Vamp is cut, and edits were made to the "Sid and Nancy"section as well.
Differences from Lady and the Tramp
In the second segment, Vamp is blue (like Marge's hair), unlike the movie, where she is tan. Also, her collar is red (similar to Marge's red pearls) instead of blue.
Vamp doesn't go to the pound, unlike the puppies. Also, in the movie, Lady was in the pound wearing her license and was not going to be put to sleep.
Vamp has eleven puppies, unlike the movie, where Lady had only four: Annette, Danielle, Coliette, and Scamp (three girls and one boy).
In the segment, Shady doesn't have many girlfriends, thus only having one: Vamp. But, in the movie, Tramp has about seven or eight girlfriends before Lady, including: Lulu, Trixie, Fifi, Rosetta, Sequita, Sewawa (or Pedro thinks that Rosetta, Sequita, and Sewawa were his girlfriends) and Peg (implied). It's implied that they are strays, as Tony said that Tramp should settle down with Lady.
The Selma and Patty siamese cats seem to live with Vamp in the segment. However, in the movie, they only appear as Aunt Sarah's cats as she is in charge of Lady, the house, and baby Jim Jr. while Jim and Darling were away.
Jock and Trusty appear as Shady's friends, unlike Lady's. However, the dogs in the segment aren't wearing collars, making them strays.
The Moe dog that looks like Bull is black instead of light brown.
A Peg dog doesn't appear in the pound. It only appears in a cameo as an Edna-like dog and only for a split second.
There are no humans in the segment, possibly to maintain the dog's perspective.
The Moe dog doesn't appear in the pound, while in the movie, Bull is in the same cage with Lady, Peg, Boris, Pedro, and an unnamed dog.
The spaghetti scene is parodied but instead of them kissing through a noodle, Vamp's head gets sucked up into Shady's body.
There are about five other type of animals eating dinner at the restaurant, while in the movie, only Lady and Tramp only have the dinner, as Lady is a Cocker Spaniel and not a stray.