This is something that Yorkshire men say when they can;t be bothered explaining something or when they give up a conversation half way through. Especially common with people born and raised in Bramley.
'So I'll explain to you why what you did was wrong.'
'Okay, so tell me'
'Well you said, oh it dunt mata'
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