Genital warts. Fine if you are a male, because you can see them, but a female with percy is very dangerous because her warts are hidden up in her wee wee
First man: I hear that girl has a very bad case of percy, and she gave warts to her new boyfriend. Now he has them all over his penis, and his tongue.
Second man: oh shit, it couldn't have been that good to risk that.
First man: Dude, he couldn't see them. They were up inside her stink.