V.I.P: Vagina In-Pocket. When you know you got a girl's pussy conquered, you know you got love-makin' in the bag, it's goin down 2NITE.
The usefulness of this word is you can talk about a girl you're about to shag around many people, even right in front of her haha, but because VIP is already commonly used to refer to a Very Important Person, she won't notice that you are bragging/divulging sensitive information.
Very diverse usage.
Lady-Killer: Bro, I have been at this club for only a few hours, and i ALREADY got V.I.P. I'd like you to meet Kandy.
Bro: Boss, bro, boss
Hoe: Hi! My name is Kandy!