The Barteller is when you are balls deep in Thomas Bartels and he screams and accidentally mutters his biggest secret. you can only find it out while trying this.
'hey dude do you know the big secret about Thomas bartells?'
'yeah its that he fucked his dog on a Tuesday with a doorknob and a pitchfork'
how the fuck did you find that out?!'
'hush my child, the Barteller"
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?"