Party Trick: (Noun) A gag or trick performed to amuse people in a social setting.

If you haven't heard by now, Lily Allen has a third nipple. And boy, will she use any excuse to break that sucker out, as seen here at an event for the radio station Z100. Not that I blame her; if I had a third nipple I'd be doing the same thing. Then maybe I wouldn't be known as "the girl who shows up to places with her own box of wine."