Mainly said by 'desirable' teens & young adults from Dublin as an affectionate pet name for an old chum that they haven't seen since D Wing in Mountjoy Prison
"Ah what's the story brother rabbit? When did they let you off the landings bro?"
"There he is - brother rabbit himself, alright pal?
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