Sounds like your XH is the one who can't let go. After all this time you are still to blame for his misery. I agree, he can't face and own up to having screwed up his life. So, what better way to try and live with himself and actions then by continuing to blame you?
Seems like he wants you to move on with someone else so that there would be a definitive reason for him to let go and relieve his guilt. He needs more fuel to maintain the reasons he left.
Appears that you have been on his mind, a lot...I'm thinking that this may be the part where I've read that the shoe starts to worn by the MLCer, and they start to regret what they've done, and where the LBS is on stable ground and continues to rebuild and live their best life.