The Dirty Volcano

When your partner is laying on the ground with only their shoulders touching, holding their legs to their head, while you proceed to have anal sex. Once you ejaculate in the rectum you grab their legs and thrust forward to the head making the semen shoot out of the anus like a volcano.

Friend: Why is the front of your shirt nasty?
You: Dude, I gave this chick "The Dirty Volcano" last night and she erupted on m shirt.