This is hot. Also, there is the fantasy where the mother is herself the bully. abusing her son physically and mentally, and also manipulating him to keep him thinking that she loves him. or maybe she actively invites and encourages others to bully her son.
Yeah I've seen some stories like that, like if her son brought a girl home, and it looked like they might be dating, or the girl might like her son, she'd act like a caring mother/cool mom to befriend the girl, then be like "oh Amy, you're far too good for my son 😂 why did you end up dating him, over the other far more impressive boys? Like I love my son, but I've seen some of the boys he goes to school with, and even I'd pick them if I could 😂. Honestly sweetie, I wouldn't even blame you, you deserve a good guy" and manipulate her son's girlfriend till she ended up dating one of the boys who bullied her son, then top it off with some "oh stop crying, you should be happy she found love with a decent man! Honestly this is why you can't keep a girl 😤 at this rate I'm never gonna be a grandmother thanks to you. You should be happy he sent you that video! Even if you didn't get to be with her, at least you got to see her getting fucked by a REAL man"
Stuff like that, or always showing off his most embarrassing baby photos to any friends he brought round, treating him like her little baby boy, while treating his friends like men, till she subconsciously planted the idea in their heads that he WAS a little boy compared to them, or always accusing him of not trying hard enough at school or sports, while praising other guys his age who did worse "because they can afford to relax, they can already get any girl they want. You're the one who has to work your butt off and get a high paying job if you want to get a girl to look twice at you".
That kind of plot stuff?
I personally love a slow burn like that, with teasing, borderline gaslighting elements of maybe it's all in his head, or maybe his mom IS fucking all his friends behind his back, and joining his bully in fucking his sweet, naive ex, but it's never outright shown or said, just suspected till the end.
Like many years later, after he's finally got a wife and kids of his own, his mom reveals it all to him, and then ends it by telling him she already helped his asshole coworker who always steals credit for his work, to steal his wife and daughters too, and was just telling him this to distract him while they got the shit fucked out of them in the other room.
I don't really read stories anymore though. I prefer AVN (adult visual novels) for that element of choice.
It's a lot easier to find avn with fucked up plots, than it is to find stories like that. Since you can't usually tell from a glance when it's just text