I'll throw this out there too..and I may get blasted for it. But if you really want to fight for him...then call her on the carpet. You know how to reach her, confront her. Sure it may piss him off...then again, he may see you fighting for him too.
Just a thought... GEL
I'm here to "ditto" GEL's thoughts, not to blast her. Confronting the OW is a bold move, but it brings things to a head. If the situation is hopeless, it will make that clear right away. (ie if he takes OW's side) If there is a chance to save the R, the M, then she cannot tolerate the OW. There is NO chance to save the M while he continues to carry on with the OW. If he won't break it off, he's not helping restore the M.
I'd say take a stand, but be prepared, as it will bring things to a head one way or the other. (which, IMO, can't hurt any more than the unacceptable status quo)
