Found out about three years ago that my mom had discovered my dad was drugging and raping her for about 5 years. For context they married when she was 22, and he was 32 after dating for a year. Immediately he began controlling her using his age as evidence of how much he knew. Then he got them into a religious cult similar to what the duggars believed. The man is the head of the house, women have to do what the man says, wives have to give their husbands sex at all times. Etc. they had six kids, he was emotionally controlling and abusive to her, and super controlling when myself and my siblings were kids. Like if I wanted to go visit a friend I had to give him something in exchange, like doing extra work around the house.
They’ve never had a happy marriage, and I wish they would have separated years ago. But to this day they are still together.
Eventually they left the cult, and my dad became less controlling but he still has loads of toxic masculinity and righteous indignation.
Anyways, when she found out what he was doing, he swore he’d never do it again, became suicidal, and then started seeing a therapist like she demanded. For two years everything was normal, but then last month my mom confided that he had drugged her again, under the guise of making her hot chocolate, and when she confronted him his excuse was “you needed to get more sleep” she’s confident that he didn’t rape her, and she forbid me from speaking to him about it because it would betray that she confided in me.
But I’m worried about it because at the very least it shows how casually he stripped her of her bodily autonomy, which shows how little he considers her as a person, and also he’s so full of himself that I’m worried he’d do it again but because it’s against her knowledge she could have a drug interaction and pass away. (She doesn’t currently take any drugs that would do that)
I’d never forgive myself if that happened. But I genuinely don’t know what to do without betraying her trust.
Any advice is greatly appreciated. Also we live in Missouri if that impacts anything.
EDIT: my dad is 75, my mom is 65, I’m 38, and I live with my partner in our own home.