The grandfather clock is performed while suspended in the air, generally with the help of 2 others. It is when you are hovering above a sleeping persons face with your dick and/or balls hanging directly over their face, waking them with either a slap or a loud noise (preferably similar to a grandfather clock striking the hour).
Dude, Robb ba ba brain'd me, so I'm gonna get him back tonight with a grandfather clock.
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