why would you even want to talk to the guy is beyond me, the hardest part about fronting a perpetrator is they will 99% of the time deny everything, its not worth the pain and frustration it can bring, i would suggest if your looking for closure , that you look within and only concentrate on you.
We burn an enormous amount of energy , thinking about our abuse, our perpetrators and so forth, and its ok if its part of our healing or closure , but at some point we have to reclaim our thoughts to a greater extent, this may mean that every time he creeps into your mind, find an exercise or activity or something that will lead you to address your thought pattern and find a positive reaction or response everytime it appears.
I would also set a clear boundary for myself , anyone that exhibits questionable behaviour or responses , i would immediately put in the background, for people like your ex, i would ensure he is cut off completely, i would then look at my own reasons for having any contact with him and address those with a therapist