What is P.O.S.P?

Pimped
Out
Secret
Spot

A cool place to chill at that nobody but some of your close buddies knows about.

A: "Hey dude, I'm bored as hell. Wanna go to the P.O.S.P?"

B: "Sure but don't tell brian about it, he's a faggot."

P.O.S.P - meme gif