I think you are doing well as you are still able to go to the gym and function on a daily basis.
I think it's natural to have that hope. I have had it before even when I didn't want it. I even have it now, but for me it's dangerous as he is a disgusting POS!
From my experience though, NC is the best way to go in this situation especially as he is with her. By contacting him, he knows you are still around waiting for him to come back, and I think if he does, he will take longer to do so if he knows you are waiting for him. It will also stop you from healing yourself from what has happened to you. Give yourself some space and time. Not only will it make you feel better, it may wake him up to what he is actually losing.