This term could be used to describe the action in which Subject A pulls down their pants to reveal a bare ass, and then does some sort of dance-motion whilst Subject B screams profusely and throws objects at Subject A's arse.
When you have a fat pimple on either one of your butt cheeks. This pimple makes your butt cheek/cheeks look like a boob. The cheek of the butt is the breast, while the red pimple is the sexy nipple!