I echo Happy Woman's advice about trying to get as much information as possible, as I genuinely think that knowledge is power. Does he work with OW, did he say how they met etc.? I think it is hugely unreasonable of him not to tell you where he is living at the moment, especially when he switches his mobile off so frequently. Try to find out as much as you can about the OW, Fading. I think if they are work mates, I'd be tempted to sit up and wait for them to leave the building, then confront them if you feel up to it.
The OW is entirely complicit in this horror and needs to face up to her own part in this. There are simply no excuses. For what it's worth though, I think he's protecting her by saying she backed off the first time, on discovery that he was married. He won't want to paint her as a home-wrecker, unfortunately.
Fading, you can certainly build a stronger marriage after an affair, but there needs to be total honesty and absolutely no contact between the affair partners. We are all different - and I respect Debs' views about knowing too much, but I needed to know absolutely everything before I could move on. My imagination was far worse than the reality anyway (though that was bad enough), but for me, I didn't want something ambushing me at a later date.
In my case, the OW was a vicious, nasty person and she behaved abominably when my DH ended it with her, even to the point of making horrible comments about our eleven year old DD. I therefore had every reason to think that she wouldn't let up and that some awful bit of information would come my way at some point. I therefore needed him to tell me EVERYTHING so that once I was on the road to recovery, she couldn't set me back.
As I suspected, she posted a fresh series of allegations on a social networking site, but as she is not the sharpest knife in the drawer, she even managed to contradict some of her own information - and without going into details, I had concrete proof that what she was alleging couldn't possibly have happened.
So in summary, I always think more information is better than too little - and if I had my time again, I would cause as much trouble as was humanly possible for the OW. I was too nice, too dignified, too scared that there would be repercussions for our children and too decent to 'phone her husband and tell him what had been going on.
Like Happy Woman, my fantasies about George Clooney have been temporarily replaced with images of the OW coming to a gruesome and painful end....!
Since I therefore love hearing revenge stories, able to share yours Debs?