It's going to take him a while, most likely. Look at it this way.... there was a good bit of time between when he left you and got together with her. It might not be as long this time, since he knows you, but it will take some time.
I think that for him it is a good thing, and probably for you, too. You want him to be over it, and detached from it. You don't want to be part of the drama.
