A sexual act taking place in the janitor's closet, often intercourse, causing the janitor to be quite shocked if he happens to open the door while the two are doing it.
Guy 1: You won't believe what happened yesterday!
Guy 2: What?
Guy 1: Stacy wanted to have sex, but we were in school, so we did it right in the closet. It was a real janitor's surprise!
by gogglyeyed October 24, 2013
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