She is saying what they ALL say. It's script. She is saying the words that make her feel justified in what she's doing. Trust me, we have all heard some form of everything you are hearing. Let it roll off your back. What she says and does is not important right now.
I wouldn't say much about the OM other than to tell her that you aren't willing to live in an open marriage. If she feels she needs to continue a relationship with him, she'll have to find a new home to do it in. If you force it, you'll push her further towards him.
I don't even think you should be focusing on working to keep her now. She has mentally left you. You need to focus on getting home safely, reuniting with your kids, and taking care of YOU.
