I agree with saltedcaramel64. For most people being upfront about the asexual part is going to be more important, especially at the beginning of a relationship. Sex is an important part of most romantic relationships, this is something that is going to likely be expected unless you are up front about your non-desires.
As far as the ABDL stuff. I agree that it should be gradual. Don't wait forever of course but at least until you can trust that they are not going to balk at it and tell all of your co-workers which would mean you're not only out a relationship but possibly also out a job because the environment can become uncomfortable if not toxic.
I consider myself asexual (I could happily go the rest of my life without it) although I still participate to make my husband happy.
On the same token my husband has become a wonderful Daddy and I'm not talking about some of the people you see that it's all about the sex. He takes care of me, cuddles me, reads me stories, gives me baths and so much more. I suppose I would say its give and take. If your determined to not do anything sexual lay the cards on the table. I would honestly say by the second date. Let the first one just to see if you enjoy each others company then start the confessions on the second date. I wish you all the luck in the world and I hope it turns out well.