Brittany: I have to take a crap, those tacos are killing me!
Fred: Then use the bathroom!
Brittany: I can't, someone might see me shitting! I guess I'll have to wait until I get home to my private, clean bathroom.
Fred: Geez, your a Stallophobic!
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.