She was reluctant to cheat at first, but once she knew how good her son's bully fucked, she was the one to encourage him to take her on her marital bed.
Bully: Time for the daily ass inspection slut. I know I don't really need to do this but it's pretty humiliating to your son. At least I'm not beating him anymore. He also seems to enjoy it, I've seen him get hard every time I treat you like an object. Ma
Mom: Flashing my slutty bits from time to time is just part of your bully's obedience training. Listen son, I have to be a proper bimbo slut for him. Making his dick feel good is more important than your feelings.