It sure is tough. Bluerain, maybe you've hit the nail on the head though. I hate the idea of moving forward with the separation if my W is still under the influence of the OM, so perhaps I should take your exact same stance. As long as the OM is in the picture, I will refuse to move forward with the separation. The question is, how do I verify she's had no contact with the OM, and how long do I require this no contact before I'll relent?
If I don't participate, her only recourse is to get a lawyer, spend a lot of money we don't have, and try to trump up some grounds for divorcing me, of which she has none. She'd have to try to claim that her unhappiness in our marriage was essentially a form of abuse I was inflicting upon her. Of course she was unfaithful, and she'd know that was a card I could pull out at any time. I know deep down she's ashamed about that, so I don't think she'd want that coming out. If she really stuck to her guns, and it was just getting uglier and uglier, I'd relent. My wanting to stop the separation is just send the message that I'm not going to tolerate her dicatating how this is going to go anymore, a la No More Mr Nice Guy.
As far the LRT goes, that's essentially what I've been doing. I don't initiate any R talk, I only contact her to discuss the kids, I don't initiate physical contact hardly at all, I always have a PMA when I'm around her, etc. Now that things have improved between us, I guess I'd say now I'm really doing LRT-lite, in that when I do spend time with her and the kids, I drop my guard somewhat and have friendly conversation, and I don't act quite so mysterious. She doesn't know all of what I do when she's got the kids, but I do answer her honestly if she asks, instead of dodging the question like I used to. The fact that she asks is interesting, I think. It funny how she does it too, like she really doesn't care, she's just wondering.