A Chocolate Nixon is when someone spreads Nutella ( A delicious chocolate breakfast spread sort of like peanut butter ) on their asshole and then has someone motorboat their ass. It's called a Chocolate Nixon because of the chocolate from the Nutella as well as the poop that may be in the ass still and because when someone does a Richard Nixon impression they shake their head violently from left to right and look like they're motorboating someone.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.