Venereal Darwinism

When the STD you already posses overpowers and defeats those of the STD that you've contracted from your latest conquest.

Ryneaux: Dude, aren't you worried about hooking up with that chick raw-dog? I hear she's got the herp!

Mocha: Naw, its gravy. I've already got AIDS, its like Rock vs. Scissors. Venereal Darwinism dude. The strongest survives inside.