when someone/something does something sneakily to fuck up your day or plans - usually friends doing it to prank you, but can be otherwise.
In Halo, when someone assassinates you from behind - they are a sneak fuck... especially when said person is on your team.
by ashpagrass December 21, 2010
ahhh this one you don’t even wanna kno where THAT came from…but ill give the meaning anyway. It’s the only way for a straight girl to nail another girl. If youre having a 3some or even a 4some (if those exist but in todays society im sure they do) and while the “hot chick” so-to-speak is having fun doing her thing or w/e u nail her. But u be really sneaky about it. Therefore it doesn’t seem as though your not straight.
by jess hanch & nikkii rodrigues July 11, 2008
When someone jumps behind you and scares the crap out of you in a most vulgar manner, mostly thrusting their crotch at your behind. The attacker usually screams the words “Surprise Butt Sex”.
by the nig thumper September 30, 2011