@parker06 you are taking in and processing a horrible, horrible realisation at the moment.
You are blindsided, forced to face the possibility that your marriage is over, that your life has changed and might change in the near future into a future you neither invited nor wanted. It’s not weakness or a reflection on you that you are still asking yourself (and us) if there is any possibility that this can be saved, that what you see as the worst case scenario can be avoided. It takes time to absorb stuff like this, we can read this then say what we think and get on with our day. You read this and respond from a state of pain, anxiety and trauma. So ignore the ‘pick me dance’ comments, whether true or not they can only serve to shame or belittle someone in deep shock. It is perfectly normal to not want something to happen, regardless of the circumstances, and try to stop it at all costs. It’s normal OP.
However, when you can bear to, you need to look at what has happened, what he has said and is still saying, and then you need to get selfish. What do you want to happen? What will make you happy? And he needs to provide that instantly. He’s already telling you that he’s not prepared to give this woman up, even as a friend.
Ask yourself if you want to live every day that he’s at work, in a state of panic and pain, wondering what he’s doing or saying. Ask yourself if you will never wonder what’s on his phone and what he’s doing with it. Do you want to live your life constantly looking over your shoulder, knowing that he’s going to go to work with a woman he had told that if it wasn’t for you he’d be with her?
It’s very hard to face stuff we just don’t want to, and there’s no shame in taking your time wrapping your head around it and making a decision. But the only way back for me would be him to end it, cut all contact and get a new job elsewhere. And he should be on his knees offering to do that, offering to do anything you want him to. That’s what remorse and fighting for a marriage looks like OP. Him begging, him making huge changes and sacrifices, him willing to move heaven and earth because he can’t stand what he did and wants to change. Unless this happens there is no way back, the fantasy imagined relationship will always be better than real life, you can imagine a scenario and colour it in any colour you like. Reality usually tells you how you actually feel about anybody. At present there are no consequences for his actions, he thinks he’s got you where he wants you, he’s got her where he wants her.
Think carefully what kind of relationship you want (and deserve) and then he has to provide that. Him. Set clear boundaries and ask the questions you don’t want to ask. “Are you giving her up or not?” If the answer is no, then it is far better to tell him to leave than live a life of torture. Take your time, think carefully and be honest with yourself about what is happening. It hurts to face the truth, it’s hard when you are in a state of trauma. Treat yourself gently but try to stick with what you can actually see, what you can actually hear, rather than trying desperately to see what you want to see and what you want to hear. I know because I did it initially. It’s the denial stage of trauma and normal. Face it in your own time. Get support to help you. You can’t dress it up any other way to make this understandable or excusable, it isn’t. I’m so sorry OP, I know that this is your worst nightmare. Put yourself first now, you owe it to yourself, you deserve to be put first. X