Top Definition
Where trombones yell suprise 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 suprise 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.
horny man 1: What sex?
horny group: Butt sex!
horny man 1: What sex?
horny group: Butt sex!
Together: Surpise Trombone Buttsex!
(then procede to engage in buttsex or trombone buttsex)

horny man 1: hey
girl 1: hey
horny man 1: Suprise Trombone Buttsex!
by creatorofsuprisebuttsex October 01, 2009

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