When a man fucks a girl in the ass, and the girl shits on the the mans chest, turns around and then proceeds to jump on the mans chest that has been covered in her shit. Thus creating a "Chocolate Moonpie".
Jimmy: "Did you hear? Tommy got Chocolate Moonpied yesterday."
Sally: "No I didn't, what the fuck is Chocolate Moonpied?"
Jimmy: "Well, Tommy was fucking a chick in the ass last night, and she shit on his chest, and then turned around and belly flopped onto his chest after she shit on him!"
Sally: "That is soooooo hottt."