Blocking the anus of someone and not letting anything pass through, while forcing other things out of the person (e.g. shit, from the mouth or the nose as there isn't any alternate path for the shit to go out.
James couldn't get the last piece of shit out of his anus, so he went through the night with anal blockade.
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