These are the morbidly obese people on news reports standing in food lines waiting for free food. You can indentify big fat fucking bums in two ways.
1. They're usually claiming no job or food but have cell phones.
2. They're generally standing in line in front of the skinny people that really do need the food.
Hey Glenda, I saw you were in that line getting free food on the news last night. You're a dear dear friend but I must tell you that you're a big fat fucking bum for doing that.
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?"