Boy you sure are a different cat. Let's throw OM3 out of the equation. You are still not listening to what she is saying! She is asking for a true separation. Does that sound like someone who wants to work on the marriage?
I agree that she may be questioning her choice with OM3 due to his availability and distance. However that doesn't mean she's coming back to you. She has stated that she is not attracted to you and I know this is going to sound harsh but I can see why. You have no backbone and allow her to treat you badly. That is not attractive!!!!!
I have no doubt that you are a great father and a super nice guy but until you learn to love and respect yourself you will struggle to keep a relationship with a woman who has options.
If you want to forever cement yourself in the friend zone then go ahead and support her. I still think you're going to kick yourself one day for not trying DB.
