butt sex is when two girls, or two guys(weird), or a girl and a guy(also weird) take a dildo, or a dildo like shaped object and stick it in each others assholes and bang back and forth
i love butt sex (actually i just couldnt think of an example and i think this shit is weird)
Sex up the buttocks, also known as anal sex, but spelt like buttsecs because it's 1337. And we all know, guys that spell buttsecs like this will actualy get more buttsecs.
awsomedood: Can we has buttsecs?
slammin girl: is that like "s" "e" "c" "s"?
awsome dood: yeh, you know it
slammin girl: what is you waiting for, plez take me from behind!!1