The art of shitting into a condom, freezing it, then inserting it into another persons anus during coitus.
Person 1: You'll never guess what I did last night..
Person 2: What was that?
Person 1: I gave the missus a Mars Bar Surprise.
Person 2: What was that?
Person 1: I gave the missus a Mars Bar Surprise.
by farmer01631 July 7, 2012