I had much the same situation with my first wife, except this was with a married coworker. She locked her phone, started taking calls in the bathroom or going to the other room, worked later than normal, and stopped inviting me to things with her coworkers (some of whom we'd been friends with since college and stood up at our wedding). A bit of time passed and all of a sudden, we went on a couples date where we went to dinner and the musical Chicago. This guy's wife freaks out and dinner and starts a big thing with him, which I thought was weird. I asked my wife about it later and she said the wife didn't like feeling like a third wheel. I thought that was weird but didn't take extraordinary note of this.
A couple of weeks later, the wife goes to NJ on business travel. Unbeknownst to me, she pairs up with another coworker to spend some time in NYC during that trip. No big deal, right, and she comes home and I'm oblivious. I'm going about my daily life and am getting home after work (wife is "working late" again) when someone calls my name. Its the guy's wife. Apparently the guy is an idiot and she figures out his work voicemail password. She hears a message from my wife saying "Hey baby, I can't wait until you get here. I miss you so much." Now I'm shaking as the guy's wife drives off. I call my wife and demand that she comes home right now. Obviously my wife knew I was livid about something. We have a very one-sided conversation that ends with her saying she's committed to me.
Soon after she asked for a divorce and said she'd give me everything. She was my "one and only" so I pushed for counseling to save the marriage. So we start marriage counseling. I go through it with the full intent of saving the marriage and she goes through it to salve her conscience and, ultimately, to make sure that I'd be okay if she left. She said some things during the counseling about this other guy being "the one" that to this day she will deny ever saying. She also swears she never actually cheated on me. This dragged out for months and we ended up getting divorced. Of course, her "you can have everything" story changed before the divorce, but I got out pretty easily.
She tried to stay friends with me for years. I had a really hard time letting her go. I really hope your marriage doesn't go the same way. But, in the end, I am now engaged to someone who is a much better fit for me. So it worked out well in the end. I just wish I could have the years of my life back.
