When someone says something so obnoxious or annoying you want to hit them and instead you have to "Flip Back!" with the intensity of not actually doing anything, or saying anything bad back. It may help to control your own snappy reactions.
"Oh Man my brotherstole my bong from me and I was like "Flip Back! He is my bro!."
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?"