John,
It looks like she is playing you John. Use's you for the comfort and security you can provide and having her liason on the side where her emotions really reside.
I would not participate in sex again if I were you. I hate to say this but it may have not been you she was having sex with.
She says she has no feelings for you but how can she find those feelings or even experience a little pain if you keep rescueing her?
Its almost like your saying " don't worry, I'll be here, no matter how you feel about me".
You deserve alot more then that John. It all may look good to the neighbors and perhaps makes the kids feel better but are you happy with all this?
I would suggest you start doing things to make John happy. To feel better about himself.
Looks to me your ego has taken a terrible beating, that your taking the lumps still while om gets the caring phonecalls and good times.

God says to walk straight in your path and let the sinners sin, as they will anyway.
You must let her experience losing your attention in some way. She has the best of both worlds right now and feels that she can carry on this way for quite some time.
I really feel for you having to live like that because I also did it and it was brutal.
At least your om does not call and ask for her.
Ron