SOrry you are here. For one, I think you were too quick on the forgiveness...or at least the forgetting part. He hasn't done anything to show remorse or that it's even worth getting back together with him.
Who knows if he's in MLC. I personally think it's mainly hogwash. It's a convenient excuse for someone cheating...a way to excuse behavior you wouldn't normally excuse. To the faithful spouse, the behavior of a cheater always looks unexplainable. I'd wager he was cheating with OW most of that time.
You can't control what he does. All you can do is make a happy life for yourself. Want to get his attention? Start getting yourself out there. Go out with friends. Find new friends. Get into the single woman mindset. Guys are simple. They want what they can't have. We don't want letters that say we are forgiven when we didn't deserve it. That's just a free pass to continue with this happy little affair while having a fallback plan. Want to be someone's fallback plan?
I suspect that life isn't all rosy with OW. He's probably getting a little wanderlust. Don't make too big of a deal out of his seeming to reach out. He has a long way to go. Don't settle for less that his full effort to prove to YOU that he's worth it.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer