A skank. A whore, a slut, take your pick. A quick easy (cheap) lay.
Guy 1: Did you hear about Sam? I heard she slept with some random dude at that party!
Guy 2: Yea man, I heard that too; did you hear about the last party? I heard she totally gang-banged!!
Guy 1: Yea man, she's such an easy cheese...
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.
FRIEND A: "Did you just take a stealthie of me?"
FRIEND B (turning phone around): "no I was just using snapchat's new filter, see?"