Robert Mapplethorpe is an artist, who apparently according to The Simpsons, has a particular interest in human derrieres as well as flowers. There was a "game" made for the failed CD-i video game and multimedia format of a collection of pictures from the artist aptly titled "The Flowers of Robert Mapplethorpe" that some may have heard about. The popular internet show The Angry Video Game Nerd has done a show that features the famous art based game, while a very small sight gag in The Simpsons has also poked fun at the works of Mr. Mapplethorpe. In the 10th episode of the 6th season, named Grampa vs. Sexual Inadequacy, the Simpson family is at the book store. While parents Marge and Homer are looking for books to help them spice up their marriage, the kids suddenly come up and in order to hide the content of the books they are looking at they quickly pick up whatever they can find, and wouldn't you know it, Homer grabs a book with the name Mapplethorpe written across the cover with a black and white image of a human posterior. As soon as he sees what he's grabbed Homer gasps and drops it suddenly. If you are a casual watcher you probably never even noticed this scene but here is an image captured from that scene for your enjoyment, along with the video from James 'The Angry Video Game Nerd' Rolfe of the game.
James Rolfe, also known as the Angry Video Game Nerd, released on his Cinemassacre Youtube channel the video: James and Mike Play The Flowers of Robert Mapplethorpe, which features the CD-i game that showcases select works of Mapplethorpe.