a sexual act in which one partner is upside (via handstand or being held upside down by another) and projectile diarrheas in the air, like a volcano erupting, while the other partner awaits below to have the diarrhea rain upon them like hot lava
damn, that nasty hoe tried to get me to go volcanoing with her last night, disgusting!
When you open a woman/mans prolapsed asshole and fill it with a flammable substance like gasoline or lighter fluid. You then light the substance on fire and watch the anal cavity explode in a firy plume of shit and possibly semen.
Adrian: Yo what are you doing tonight?
Steven: prolly gonna be volcanoing my girl tbh.
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?"