I know a guy who really fucked a couch. He stopped because his stepdad found out and explained to him that something terrible would happen if he kept doing it.
Anyway, he's the raddest anarchist I know and the only couch fucker I respect.
Edit: I should say, he's the couch fucker I respect the most.
I may or may not have seen a number of porn vids online of guys screwing a fleshlight or object wedged between couch cushions or mattresses or pillows in my travels.