Baltimore Oyster Shuck
The male is standing up and the female is laying on the bed on her side. Right before the guy skeets he yells out "Yahtzee!" and skeets in between her butt cheeks. The skeet acts as the actual oyster and the cheeks are the shells.
I gave this bitch the Baltimore Oyster Shuck last night. I spread her butt cheeks back and forth and found a pearl.