Abby - I hate to say it, but I kinda wish you had gone, waited for them to come out together, and confronted them.
NOT that this is usually good advice. But I sense that you keep being held hostage by his lies - so long as he won't outright admit he's still seeing her, you can question yourself and hold onto that tiny shred of hope that there really is a legitimate explanation for everything you are seeing.
You can't confront him now - as you've said, he's already got his "legal" excuse in place.
I'm still for a private investigator in your case - I think if you had photos and proof that they are still carrying on, it would break the impasse you are in. Maybe for bad, maybe for good - but you can't keep on the way you have been, can you?
