Resources to defensive partners and unkind metas

First of all, I recognize 80% of the issues I have with my meta is due to the hinging of my partner and myself for enabling rescuing for both him and his partner.

My partner 39(M) has been seeing his gf 52(F). There's been a lot of issues between the three of us, mostly my reactivity due to him cutting off connection (physical and emotional) during grad school while I begun trauma therapy. Bad timing.

I have always tried to be accountable to my actions, met up one on one with my meta- own my harm, say my hopes. Welcome them into my friend group and life. I got into more spiraling and reactivity because I was not ready for it.

At his graduation he cheated on me by having no condoms with her, not telling me and then again with another partner. I was devasted. Usually when some rupture happens she and I are able to talk. This has happened while I was on the grand canyon river trip for 26 days and my partner bought tickets from her friends for a music festival. During the festival they both failed to communicate with each otherand she asked for three of us to meet and I met, listened to her feel taken advantage of (my partner did not say anything) and I apologized for the impact that she felt. I expected something the same when I learned that she had knowingly crossed our boundaries. I don't think I expected much from him because he had pulled away so much from me but I had hope she would care about me through the struggles and the ways I showed up. It's not her obligation but from the "friendship" and kitchen table we were aiming for (couldn't get my partner to help in any of this) I had hope my hurt would matter. She refused to meet with me, said it was her business.

My partner and I couple therapist recommended that her and I don't co mingle anymore. I objected because I knew it would come back negative at me. And it did. She thinks it's a descalation in her relationship with my partner, despite she sees him more, she still gets to see our friends, and they have sleepovers at our house. It's only her and I don't meet. When we are in the same event she storms away and refuses to say hi to him. I feel like shit. She texted me that she doesn't want me to talk to me and that was 4 months ago.

When I try to talk to my partner about this he gets easily upset at me. He is self preservation but it feels like he is aligned against me with his partner. Neither one have been accountable for the rupture, especially him. He was more upset about losing the second girlfriend than when I told him I wanted him to move out. Since not Co mingling it has been calmer in the house but there's still this unsafe feeling. I can't talk about the event, I can't ask what is happening- he says he wants to stay out of it and leave it for us to figure out. But if she storms off and tells me to not talk to her how am I supposed to do that?

When he doesn't t communicate he get reactive to me because it always around his failure to inform about things with them. He says she's safe and I am unsafe.

I asked him one time to please work on our relationship before getting more and he said he would never do that. She got mad at him for dating again before working on their relationship and he turned off the apps.

I don't know how to manage this because I feel like a fail to both parties and I'm in a sunk cost marriage. I have my own trauma and I just want to feel secure. I know I abandoned myself at the beginning and now holding boundaries I am getting this kind of behavior from him.