An exclamation made when your friends or family are teasing you to a point where you can't handle it anymore and a hissy fit is in order.
Derived from a YouTube user's famed outburst following Britney's lackluster performance at the 2007 VMA's.
Sarah: 'OMG Susan, I can't believe you are wearing the same skirt as yesterday. Oh, and by the way, EVERYONE knows what you did with Kevin on the weekend. Plus you look a little fat, are you retaining water?'
Susan: 'LEAVE BRITNEY ALONE!'