When you piss around the wall of the toilet, trying to not hit the water to make little noise. Most people do this cause they're insecure about their pissing.
When someone is overly pissed off and decides to yell at everyone, even when they're trying to help.
Guy 1: What the hell do you want? You're not helping me!
Guy 2: Woah, dude. Don't be such a Pissy Pants.
Guy 3: Yeah. It looks like You Pissed Your Pants.
Pissed off Angry Pissy Pants/You Pissed your Pants
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?"