AITAH for distancing myself from my bf’s mom and suggesting him to do the same?

Hi friends. I (23F) have been dating my boyfriend (Jay, 23M) for a year and a half now. At first, his mom (Jill, 43F) was extremely nice to me—complimenting me, giving me jewelry, acting warm and welcoming. I even told Jay how grateful I was that she made me feel so accepted… and that’s when he told me the truth: she actually hated me.

That shattered the trust I had in her, and since then it’s been a constant stream of weird, passive-aggressive, sometimes outright cruel behavior.

For context, my Mom is a two time cancer survivor (lung and brain) and Jill knows this. when trying to have a meaningful conversation with her I mentioned how I had never experienced death in my life as an adult and was worried for how i’d handle it. Jill replied, “Well… your mom,” like she was predicting her death. After staring at her for a few seconds I just replied “ yeah … I distanced myself from my mom out of fear of losing her, Jill said, “Yeah, that’s what I’m doing with [Jay’s little sister] right now,” who was just leaving for college.

She’s made “jokes” about Jay choosing the wrong sister when I showed her a photo of my family. She’s refused to post pictures of me even though I’m in every family event, telling Jay, “I don’t want some random girl on my Facebook”—but she made a Flipagram for him and his ex.

She even made a dig at Jay for carrying a backpack when we go on walks—something we always do—and said, “You never carried a backpack before her. You know who carries backpacks? Heroin addicts.” (I wish I were joking.)

Because of all this, and much much much more, I haven’t gone to Jay’s house in over a month. I’m well past my breaking point. But now that I’ve pulled away, she’s gone full nuclear and is taking it out on Jay.

She makes comments when he stays over at my house, like, “How does it feel sleeping under another man’s roof?” and says it’s disrespectful that we sleep in the same bed. She constantly implies that I’m manipulating him and acts like he’s incapable of thinking for himself if he doesn’t agree with her.

She’s also said incredibly inappropriate things to him directly—like telling a nurse he’d be sleeping in her bed, saying she’d crawl into bed with him while he was sick, asking if he wanted to be “the white boy on her roster.” and making odd sexual jokes about herself to him. It’s deeply uncomfortable for him and me and he has tried telling her it’s not okay but she still continues to do it.

I’ve never yelled or been dramatic. I’ve just drawn a boundary— and her behavior has shown Jay her true colors as well so now I’m the bad guy. She acts like I’ve “turned him against her,” but I’ve done nothing except step back to protect my own peace. But now i’m scared she’s using this to turn his extended family who I loved against me. I have to go to his baby cousins birthday this weekend and I’m so scared to see all of them.

So… AITA for refusing to engage with her anymore, even if it’s causing tension between Jay and his family? And what do I do from here? I feel horrible causing this rift between Jay and his family even if he says it was bound to happen anyways.

Thanks in advance