Tl;Dr: My stepmother is an absolute snake in my family. My dad is a blue pilled cuck who's afraid of another failed relationship (told me himself) so he's going down with the ship. Yes my dad is loaded and the bitch is enjoying the ride and acting up her "fibromyalgia". I suspect she is going to try to claim my families shit when my dad dies and I don't want that nor I want her in my life.

She first showed up about 10 years ago and one of the first things she said to me when I was a teen was: "I'll put your dad against you if you don't behave" obviously nuked any trust I could ever have on her. Told this to my dad back then and he just brushed it off as I might have misheard or "she didn't really said that" She then preceded to snake up her way into our family bringing her own kids in for the ride too. My therapist back then told me: "you wouldn't want your dad to meddle in your relationships do you? You shouldn't do the same to him" and I took the advice, thought it was an unspoken rule (big mistake) and that I'd let things play out.

I got a gf and they meddled into our relationship even to a point to have our cleaning lady report to them. No more cleaning lady then. Always trying shit like going to our house to "give" shit etc... Obviously fuck that therapist and that advice. All formalities are off.

My mental health declined a lot this last 2 years (OCD) and I lost a lot, and back living at my dad's. I'm on a mission to become yet the best version of myself OCD not included, fitter than ever, spinning plates and no toxic people in my inner circle that includes this bitch.

I'm usually a stoic guy but I believe even the stoic must act when faced with some things they don't like.

Now it's obvious their relationship isn't well, and my dad overcompensates by taking her every month out, expensive stays and dinners. They don't even sleep together anymore. It is also obvious to me at least that she doesn't respect him just his money. She acts up, "oh my pains", "oh my vomits" when things are tense and just like that my dad cucks up. I'm surprised he's not caught up after a decade or her admitting her acts on social occasions like at the DMV.

I know I'm lowering myself to her level but honestly I don't give a fuck I want to RedPill my dad and take her off of my life. Any tips on how to achieve this?