This is an adjectival expression best used to describe people, places, things, moments, and events that are so annoying/stupid/ridiculous/grating that patience diminishes, moods deflate, and the threat of violence increases. Basically, this phrase can be used to describe anything or anyone that grates on your last nerve.
The fact that we are having a departmental meeting to discuss cover sheets and TPS reports really makes my ass hurt.
A phrase the homies use after they're super drunk and all sleep in a bed together, unknowingly having sex.
Homie 1: Yo last night was crazy bro.
Homie 2: Yeah man I barely remember anything.
Homie 3: Yeah we gotta go home now man.
Homie 4: Why are we all sleeping in the same bed?
Homie 2: It doesn't matter bro.
Homie 3: Why does my ass hurt?
Homie 1: It's nothing man.
Homie 1 Had total recollection and was actually the one who had a fivesome with the homies
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?"