When you see a girl who is way hotter than the guy she is with, that is an unproportionately hot girlfriend. She is unproportionately hot compared to how hot he is.
Dude, your girl is a 10! But you, you're more of a 4. She is definitely an unproportionately hot girlfriend.
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?"