When Justin Bieber's balls drop
A way of saying "yeah right" or trying to say something's never going to happen because it sounds so rediculous. Synonomous to "when hell freezes over"
Derek: "Hey Dan can i borrow your car tonight?"
Dan: "No"
Derek: "Come on dude please. Won't you ever trust me."
Dan: "Hell no. I'll trust you when Justin Bieber's balls drop."
Dan: "No"
Derek: "Come on dude please. Won't you ever trust me."
Dan: "Hell no. I'll trust you when Justin Bieber's balls drop."