The Simpsons season 19 episode 12
Episode title: Love, Springfieldian Style
Homer and Marge celebrate Valentine's Day by going on the Tunnel of Love ride at a carnival, but they end up stranded when Bart pulls a prank involving gelatin. To pass the time, Homer tells the love story of Bonnie and Clyde, Marge tells her version of "Lady and the Tramp," and Bart tells the love story of Sid Vicious and Nancy Spungen.