I'm sorry I don't think there is a lot I could offer with regard to this. From my perspective, perhaps the best thing to do may be to simply ignore what your ex is doing. I realize that's easy to say. But I, at least, can't think of anything you could do that wouldn't likely just make matters worse. What your ex is doing, it sounds like to me, is trying to get a "rise" out of you. And chances are a negative response would could be just as reinforcing as a positive one simply leading to more attempts on his part to get your attention.

I don't know if this will be of any help however here's a link to an article, from PC's archives, on the 3 "secrets" of outsmarting a narcissist:

3 Secrets to Outsmarting a Narcissist (By Not Trying to)