Mapplethorpe is a photography book by Robert Mapplethorpe.
While shopping at Books! Books! and Additional Books!, Homer and Marge were looking for a book in the "Martial Relations" section to improve their marriage. Meanwhile, Bart and Lisa shopped on their own. When the children returned, Homer and Marge quickly grabbed random books to pretend they were looking for something else, not for books about sex. When Bart asked what Marge and Homer were looking at, Homer answered "I was just pursuing my interest in... aagh!" and screaming threw the book away when he saw the pictures in the book.