Where trombones yell surprise buttsex and bang their bells together so that the noise echos in the room. Before engaging in trombone buttsex it is encouraged to lube your self up with cream, slide-o-mix, water, or all of the above.
Usually gets strange looks from everyone in the room.
It doesn't have to be with the brass trombones, because trombone is also a code word for boner. It is possible for a man and a women or a man and a man or even a women and women (if parts are there) to engage in surprise buttsex.
just go up to the partner, yell suprise, and pull down your pants and their pants and in engage in angry buttsex without lube.
Lube is optional but if u want to feel anything tmrw use it.
When the spy, featured on the PS3, and PC game, Team Fortress 2, attempts to stab you (one of the 8 other male characters) in the back, but instead, gives you "Surprise Buttsecks" after, the trending songs and videos on YouTube.
*The Blue Scout, is defeating the red team when suddenly-*
Spy: "SURPRISE BUTTSECKS", BUTTSECKS, B-B-B-B-B-BUTT-SECKS!!
To give someone anal sex at an unexpected time, or place. Perfect for those special moments.
A: Me and my gf had a really romantic date last night. Saw titanic.
B: nice
A: yeah, and then when that stupid boat sank, i gave her surprise buttsecks!!!1 kekekekeekk
B: WTF??
When going at it like dogs, the penis, moving quickly, then ejects from the vagina and enters the anus, often resulting in pain and extreme terror/pleasure.
Often to calm the victim of this "surprise", the penetrator yells
"SURPRISE BUTTSECKS!!" in a vain attempt to make light of this magical , yet, often horrible experience.
Man: Oh yeah baby
Woman: Harder!
Man: opps i slipp.....
Woman: Ow. OWWWWW!!!!!!!
Man: Surprise Buttsecks!!!!!!
Woman: this date is over! Bus driver let me off here!!!!!!