Yeah that trend started from manhwa "toying with daddy". I haven't read that manhwa though. Yes the name is exactly what is going on. A girl's mom is fooling around with much younger hot guy (like, her daughter's age. The daughter is 22 and guy is like 25-26) and the guy is probably slightly M and girl awakens her S tendencies or smth like that. Still can't believe how you can sleep with a guy who has had his mouth on your mom's kittycat T_T. I can have slightly wrong synopsis though bc I don't like any of these tropes, cheating, age gap, love triangle potential, stuff like that its a no for me T_T

This is oddly specific but seeing this trend in reels makes me wanna read it.
Any story where they get slapped in anger and they like it and just smile..?