You or your partner takes a shit and the guy jizzes all over it. The shit is the sweet potato and the jizz is the marshmallow topping. Now, you dine on this delicious desert!
Guy 1: Me and my girl wanted to spice up our night with a desert. So I pinched a loaf and she jerked me off all over it. We had a delicious sweet potato desert. Yum!
Guy 2: Dude you are gross. I just threw up in my mouth.