A funny misspelling of "butt sex". Used sometimes in funny internet pictures depicting animals trying to talk like humans. Because of their diminished brain power, they talk/type like an uneducated person.
We iS haviNg angRy buTsEks in u roOm!
Get the butseks mug.
The But-sex. Basically Yaoi in its most graphic form, which though very graphic also ends up being absolutely hillariouse!

you may be watching sensitive pornograph and all of a sudden there is man-cock on the screen and then flashy sequences of them having kinky kinky man sex and all you can do is roll on the floor laughing shouting things like Man-Cock and Penis-hankerchief!

so thus Teh-Butseks is Comic Yaoi.
Best example of Teh Butseks:

When playing Absolute Obiedience (Yaoi dating game) watch out for the Penis-Handkerchief moment, hillarity will ensue, you will understand.
by Mortal February 1, 2008
Get the teh butseks mug.