When you whack off and cum in your hand, then you run up to someone, slap them in the face with your salty hand and shout "Seagulled!"

Seagulling is a variation on the sexual practice of bukkake, with the crucial difference that in this case the recipients are unwilling.

One person learns about two people that are going to have sex and works out the location of the aforementioned event. Then he gathers as many guys as possible and packs them into the room where it's going to take place. The guys hide in cupboards, behind curtains - basically, wherever there is a place to hide. Then when the couple look like they're about to finish, everyone runs out and ejaculates all over them and then proceeds to run around them, flapping their arms like birds and making seagull noises.

A ritual which is popular in all-male prisons, whereby said inmate ejaculates into his palm and throws it at the next unsuspecting prison guard who walks past his cell.

when you ejaculate into your hand then go up to someone you know or an authority figure and throw it in their face.

The act of spunking on your hand and flick/throw it at someone.

seagulled

to cum into your hand then chuck it at someone, like bird shit
also, if a couple are dogging, or just having sex in a car you wank onto the car so it looks like birds have shit on the car