An ass scab is a person with asshole friend/spouse that trys to fix the problems/situation the ass has caused
Ass: wtf you are mcdonalds and you are out of cheese burgers? Friend/spouse: im sorry he/she is being an ass. McD's worker: dude im already angry dont try to be an ass scab for that ass
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