Well, that would be cucking his dad. So I guess, it will remain platonic for awhile. Maybe his dad will ally with the villains, get disposed off and thereby making Mama Rosa single again.
Cheating with your stepson would be frowned upon, no matter which age and culture, no matter how loveless your marriage is. I doubt Demonio would do anything that would potentially besmirch the public image of his precious mamas. Not refraining for his father's sake, but for Rosa's (at least as long as she doesn't directly ask for it).
after re-reading chapter 12.1 I think it's the guy from the Carmace family he beat in the Magic Practical Exams that ended up in class D because of his loss. The Hair looks the same
MC already fucked 3 moms, STILL havent fucked his step mom
Wonder what her reactions gona be when she learns whats going on between the other mama's and him kek