So you are still sleeping in the same bed? She probably feels that this OM is the love of her life and he "really" gets her. I am going to guess that she says their relationship is "easy" while the one between you and her has always been "difficult". She feels that all those years with you, she has been missing out on "life" and this guy is offering her the hope of a future that is very different from the one she envisions if she stays with you. You on the other hand are afraid that if you let her go now she won't come back and if she does in the future, you will be so hurt you will not take her back. You understand you did not have a happy marriage but you don't understand why she had to look for someone else to fill her emotional needs. She thinks she tried everything to get that from you and does not understand why you did not respond then. Now, she has nothing left to "give" and she is tired of taking care of you and needs someone to take care of her. She does not think of you as "the one" anymore. I know all this because I am getting it from my own WAW and I know how much it hurts because what does not sound like a gross exaggeration, sounds completely distorted or is factually not true and you have evidence to prove it. The key here, I think, is that you have to figure out a way to make her fall in love with you again and fall out of love with OM. Logistics, finances, and other practical concerns are important to her and may cause her physical body to stay around but her mind is gone into fantasy land and it won't be easily dragged out of there. I hope it can be done before is too late but right now I have no idea of what to do about it myself.
Me 39 W 37 S 5 D 2.75 Married 12 years Together 14 years Bomb Dropped 08/16/10