I do understand the depraved thrill of a respectable, loved woman falling for a sexually aggressive delinquent. However, it occurs to me how much of a mind fuck it would be for the protag if the delinquent, through the mother's influence actually did grow, achieve, succeed as a man...while remaining or even increasing their sexually dominating relationship. I see a lot of the "he treats me like a woman", but I'd like to see the bully, the aggressor, actually "man up" and do things other than fucking to take care of his woman. Protect her, support her, AND fuck her brains regularly. Not just demand and allowance.
So, aside from fucking his mom, let the bully actually become someone for the protag to emulate. I think it would be interesting for the entire family find their place under him for reasons other than fear.