Often think "what would I do if we didn't have kids?" Just don't know today.
I understand what you mean, but that doesn't do you any good to wonder "what if". You need to deal with the facts. Fact is....you do have children. The next fact is that your W is attracted to OM and she does want a M simply as a backup plan. So, what are you going to do about that? My suggestion is to drop the rope and move on as if she would not be a part of your life any longer. It is all about attitude....can you do that?
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!