A canon aspect of Blaine Anderson (from glee)'s sexuality since circa episode 4x16, Feud, but popularized much earlier, thanks to the wonders of Blaine's ass and fanfiction. There are still debates around its canon-hood, probably because its almost too good to be true. We here at UrbanDictionary have patience and sympathy for that. They'll come around.
klainer 1: hey, do you think kurt ever tops blaine?
klainer 2: of course he does, bottom!blaine is canon! didn't you watch feud?
klainer 1: I did, but I thought it meant switch!blaine or versatile!bottom!blaine is canon?
klainer 2: oh honey, that "not really?!" had zero conviction. i betcha also thought we were supposed to believe kurt never picks out his clothes.
klainer 1: wait, so... you really think he wants the D
klainer 2: he wants the D
, and only the D