shark tail

When you dig a girl out that's on the rag and then pull out and cock stamp her forehead leaving her with a nice shark tail stamp in plain view.

Used for women who refuse anal, or just because it's hot. While the girl is face down while you are ramming her from behind in her vagina, in mid-pump, you come down with a judo chop to the head but keep your hand on her, forming the shark fin. It should be of sufficient force to knock her out. After that, you put it in her ass. Hence the tail.