Means 'Oh Fuck' in portuguese. Made popular when, a famous portuguese singer (who always wears sunglasses in door) fell of stage on national TV, and the show host jumped in the air ninja style while saying 'Ai Fodasse!' (Know as Manzarra), trying to save the singer (known as Pedro Abrunhosa)
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