1 definition by The Dichter

When a Female squirts into a Male's mouth, then the male quickly spits it onto the Female's face, giving her a grenade-like splatter all over her.
We had an amazing time at the party last night! Some girl and I had sex, and I ended up giving her an unexpected Flash Grenade.
by The Dichter October 16, 2015
Get the Flash Grenade mug.