You know, Deb, the OCD thing is an interesting point. Obviously, having the kids living with you would be a huge strain for him with his OCD tendencies. (BTW, if he's willing to semi-admit it, I wouldn't be surprised if he really does have some form of OCD. Besides the tidiness, does he have other OCD traits? Numbers, tapping, phobias?)
But another thought I had is this: you see, my son with the mild Tourette's (OCD, ADD and tics) will get really "stuck" on an idea. It could be resentment over getting spacers at the orthodontist (because he'll be getting braces soon and it means he can't eat his favorite gummy bears right now) or some perceived injustice or whatever. Normal kid stuff, except a normal kid would grouse about it and then MOVE ON. S14 will perseverate, I can see the thought is cycling around and around in his brain without extinguishing the way it normally should. And no amount of trying to argue him out of it or rationalize things to him will help - the only thing that works is distraction.
Could it be that, in your H's case, thoughts of the OW are repetitively cycling in an OCD way - that is, the thoughts are intrusive and repetitive and don't "shut off" after a few spins like they would in a normal person? Although it is normal for a WAS to have trouble letting go of the OP, and we both know she's doing everything she can to hook him back in - it seems to me that in his case, there might be an oCd quality to the obsession with her. If that's so - all this talking with him about her and trying to rationally argue your point with him may not only be fruitless, but may escalate the problem. Maybe it would be better if you can try to (not too obviously) distract him and redirect the conversation when she comes up?
Plus - you keep reporting how often he emails you. YOU need to email him. Send him light, funny emails (if you are not on the receiving end of those, go to sites like ebaum's world to find stuff). And flirty emails. Short, sweet, light.
