Based on one of my weird dreams. Mordecai, and Rigby are at a trendy party, and as a prank, Mordecai sneaks up and yanks Rigby's pants down revealing his tightey whiteys to the whole dance-floor. To make matters worse, Mordecai takes pictures of it, and sends them to everyone in town. It's going to be a while before Rigby lives this one down.

Part 2: http://www.furaffinity.net/view/15012629/