on a certain day of the week (mostly on mondays) someone might feel retarded or simply stupid. Some beleive it is caused by vaginal fluid that may be in the brain. It is normally caused by fatigue or mostly a hangover.
"holly shit today i had at least 87% vaginal fluid on the brain!"
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?"