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The act of slapping a body part to sound like you are masterbating.
Guy 1: ( Clap Clap Clap Clap )
Guy 2: Dude what are u doing?!?!?
Guy 1: Dude it's okay im just mastercating!
Guy 2: Masterbating!?!?
Guy 1: No no Mastercating! Im just pretending to masterbate.
by Big Pimpin69 November 03, 2011