> When do I just call it quits?
If your partner's mom was treating them this way, or if your son was being treated this way, when would you want them to call it quits?
I know you well enough to feel good about making a suggestion, but I can share my data point: I called it quits with one of my parents after putting up some boundaries (~"I love you but it doesn't feel good when you call and text me every few hours or unexpected show up at my work") and they responded very negatively.
My metric: if anyone (from a total stranger to a romantic partner) ever talked to me that way, I'd cut contact immediately. We have no obligation to be outlets for abusive behavior. I'm probably going to talk to a therapist about it because I want to make sure I'm covering all my bases, but most of the time it feels like a net positive to have called it quits.
I hope you can find some peace and balance, with or without the relationship with your mom. I'll be thinking of you, and I'm happy to chat if you're ever looking for perspective from the other side of the fence.
Also: https://old.reddit.com/r/raisedbynarcissists