what you say when nervous, in trouble, or have just done something seriously stupid. Also can be substituted for cuss words, and person witnessing others stupidity can call flubumpst, like calling them a dumbass.
"what the flubumpst?" person 1 "Hey man, your fly is undone." person 2 "aww shit." person 3 "flubumpst." shit damn fuck dumbassidiot
Person 1: It's totally superfluous when someone says 7am in the morning.
Person 2: Oh yeah, that does seem pretty fluumptious
Person 1: Yeah it wa- what the hell did you just say?
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?"