to rub your hand up the crease of your buttocks and around your anus, then ambushing an unsuspecting victim with the same hand ih their face (whilst shouting 'mub' at them)
mub is bum backwards
mub is bum backwards
by brewlio May 11, 2007

whilst one all fours, naked, he parts his buttocks at the party ahead and exclaims "look at my brown eye !"
by brewlio May 11, 2007

by brewlio May 11, 2007
