That asshole teacher who always fails you because he has a fetish for giving people Fs. He often has a high-pitched voice that makes your ears bleed, and uses that voice to insult you to no end and speak in sentences longer than required. Favorite words include gay, fagola, ass-signment, and F.
Mr. Higglesworth: Well, Fagola, it appears you go approximately zero wrong on your ass-sighnment. Therefore, your score is exactly F out of 12, you failed!
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?"