DD, I'm going to be the minority voice here, but I disagree with part of your approach. On the 180 piece, that is, being a great husband- I agree with you 100% and you should continue as you have been!
However.....
This happened to you once before. It wasn't handled properly then, which is why you are back. Critical changes, like honesty and openness, we're never made in your marriage, so she's right back in another affair. Let's say this guy dumps her too. What then? She'll just do it again. And again.
In my opinion, you must expose the affair. It's the secrecy that fuels the fantasy. Once the secrecy veil is pulled off, it becomes real- and generally it becomes more hassle than its worth. As long as the affair meets your wife's needs, and the needs of the OM you will be in a stable "triangle" relationship (also known as "cake eating"). Right now, forget the b.s about you being the "better choice". Dont make me laugh! THERE IS NO CHOICE!!! SHE HAS BOTH OF YOU! It's the best of both worlds for her! You can be the "better choice" when she HAS TO CHOOSE, but not until then. Right now, you are just allowing their bond to deepen, while you sit and take it. Is this how you want to live your life? Man up! No woman wants to be married to a pushover, and that's what you are acting like.
Once the affair is out in the open, then you can let her know that you want to be a great husband for her, and have a great marriage, but you need the both of you to work on the marriage, with NO contact with the OM. That simple.
Oh, and no wimping out and threatening to expose the affair to the OM's girlfriend etc., she'll only threaten to leave you if you do.....and you'll probably cave....Trust me, I wimped out and tried that at first. Only kept her in the affair. Later on, I manned up and pulled the trigger without her "permission". It's the only reason we're happily married today. Getting her away from the OM cured her like penicillin!
You don't have to take my advice. My marriage recovered. Where are the marriages of those that advise you sit and be a nice, compliant, blind, husband? My two cents, I'm a little fired up today .
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