A person who opens a line of communication with you only because they believe it will
lead to their invitation or knowledge of a party.
(this just happened and inspired me to write this)
Party Sniper over phone: Hey whats up?
Me: Nothing much, just out of state visiting family. I'm on the internet being extremely bored. Whats up with you?
Party Sniper: Oh, ok, well I guess I'll talk to you later.
Me: Dude you're such a party sniper.