My guess is your wife felt sorry for OM, and he showed a lot of appreciation for her concern and interest.... and this made her feel good.
How much contact do you currently have with your wife? I imagine the times you do get to talk with her are when you are taking turns with the kids. I wish I had some great advice here, but the only thing I can think of is when you do see her, even if it's just for a short time, think of something you can honestly compliment her on, or thank her for. Even if it's just something with the kids. Don't expect her to believe you or thank you for this. Just kind of do it and then quickly change the subject and ask her something impersonal about her self or something going on. Keep the conversation as light, friendly and impersonal as possible.
Even if she hates you and blames you for everything on earth, eventually, your being pleasant will cool her down. I know.... my husband would say and do anything and everything to create a fight and get me mad. I finally learned to stay calm, pleasant and even apologized for any "misunderstandings." Eventually my niceness wore him down. Although it did take time. This was all very gradual, and sometimes I'd make mistakes. But I was determined to change the negative "memories" he created about me and the marriage (seeing everything as bad), into something more positive. And the only way I could do this was by trying to create a good impressions and "memories" in the present.
