What do I do?

[mvgfwd2]

You are not condoning the A by staying. Set boundaries of what you will not allow in YOUR home. Read up on boundaries. If one of your boundaries is NC with OM then state it and take action if violated. I'm not talking about controlling her but doing things you can do.

Maybe send her to the couch, or other actions you can take while in the house. Being out of the house YOU are the one inconvenienced by the A. It should be the other way. Maybe cut off the cell phone or internet access if you are the one paying for it. Let her get these herself if she's intent on maintaining contact. Why are you facilitating an A with family money?

Actions, not words. You're not saying W can't contact OM, she has to make her own decision, but if it's one of your boundaries then take action to get it out of your house.

I required complete access to all communication channels and NC with multiple people. Fortunately, my W complied and she will tell you today she is so much happier getting all those negative people out of her life. But I had to lay down my boundaries first, then after a few weeks the fog started to clear for her. It took getting the OM and other facilitators/supporters voices out of her head to make that happen.