Is it legal for a 23 year old male to date a 16 year old female in NYS?

It's not a good idea, regardless of the legality. A general rule of thumb for sexual activity for children under 18 is that there should be no more than four years' difference in the ages of the partners. The reason for this is that there is too much of an emotional power difference in the partners. This can be very emotionally damaging to the younger partner. If the partners really feel that they are in love, they should discuss the matter openly with the child's parents, who (hopefully) know the child best and have the child's best interests at heart. It is difficult, if not impossible, for the adult partner to be completely unbiased in the matter.

If the parents are not available for the discussion, then forget the idea altogether. It is just too emotionally dangerous for the child.