Often said by people to bully 12 year old boys with below average penises. Basically, if you know any 12 year old boys that like trump, wear neon clothes, act gay but arent gay and have a ''J'' name, make sure to remind them it's very small and nobody will ever fuck them.
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?"