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.