"So... what's new with you?" Do I have to tell the birthfather about reunion?

My DD's birthfather and I have always had a rocky relationship, lots of on and off and fights and backstabbing etc. Even into our adult years when we married other people, in navigating search and contact with our DD's birthfamily there have been issues. It's something that has caused me a great deal of struggle and pain, but over the past few years in particular we've maintained seperate lives and I've been able to put most of it behind me. I wish him the best, and I no longer harbor bad feelings but I know it's best for us not to be actively involved in eachother's lives. I recently had to contact him regarding a school reunion, (which he is NOT going to.... PHEW!) and he ended the e-mail with "So, what's new with you?" And I began a cordial reply with all the good things in my life: marriage, children, work accomplishments, and I realize that the one HUGE thing that's new, the biggest news of all, is that I've reunited with our birthdaughter. I know that he has always been interested in reuniting with her. But five years ago when I found her as a minor, I shared the info knowing how he felt, and he went ahead and contacted her behind everyone's backs, including her parents. It caused a lot of issues for me in my own contact with DD's family, and the fact that he went out of his way to hide the info from me after specifically telling me he would share any contact he had really left me feeling betrayed. Even though DD is now an adult, I feel as if he'd do something similar leaving me to have to deal with issues in my reunion. I just don't trust him. The thing is, I also know that DD wants to eventually reunite with him too. She did tell me that she wants to seek him out when she is ready, and I agreed to help her with that since she mentioned she doesn't have his contact info. I do bring up her birthfather here and there in our communication, but only to reiterate that it's a topic that I'm willing and open to discuss. I've also sent her pics of us when we were her age so she can compare features. She and I are still fairly new in reunion ourselves, so my guess is she isn't ready to begin contact with him just yet. I know that their reunion is not my place to be involved, and I'd rather keep my involvement to to the sharing of info variety. Part of me feels sneaky deliberately leaving out this piece of info, especially knowing they are both interested in eachother. If the tables were turned, I know I'd want to know, even if it was just to hear how she was doing. I know I felt hurt when I learned that he withheld the info from me. But I keep thinking "fool me once, shame on you...." and he's fooled me 865,000 times. I seriously do not trust him, even though the worst he can do is find her on his own and contact her, which he could do anyway. Still, is it wrong to withhold it for purely selfish reasons? Advice?