I am always amazed at how the WAW's think that no one else will want their LBH's. It seems to come as a shock to these brilliant women.
Why is that?
It is because of the WAS' negative self-talk. She spends so much time telling herself (and her friends) the things she hates about her husband, and she becomes convinced that that's all there is. It's all she hears.
But, of course, new women don't see all those faults. They see the attractive side of the LBS, which WAS has forgotten about. So, LBS finds a new woman, and starts being happier, and looking more attractive, and WAS suddenly sees what she was overlooking before. AHA! He is funny, or enjoys fine restaurants, or is an interesting conversationalist, etc. But now she is odd man out. And, if there is no OM wooing her, then she starts to reconsider what she has thrown away. And if that's what she really wanted to do.
Not saying it always brings them back. But many times it does. In my case, it made me aware of something I had not noticed before. That is, the spiritual part of both of us that had intertwined over the 30 years we were together. It's a subtle thing. Hard to notice until you try to rip the fabric of the marriage apart. But it was there, like two tails that had grown from each of us and become intertwined. And that didn't rip. That connection was strong enough to get both of us to a Retrouvaille weekend to see what could be done. And from there, it all fell into place.