When one sits at the end of couch so you can't lay down and fully extend your legs, just as your about to extend your legs and lie down. (Inspired by "cock block")
I was just about to lay down on the couch and my wife totally couch blocked me!!!
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi