I don't "wait for sex". Sex is only one of the things I'm looking at usually.
Unless the woman makes it plain she just wants a sexual relationship (that has only happened twice) I assume she wants a progressively closer relationship leading to commitment because that's what nearly all women seem to want, from me anyway. I go into dating because I find her attractive and i don't see any red flags and I try to get to know her in every way that matters, including sexually.
What usually happened is she decided I would do nicely but I was not sure. Once she decides I have to make a decision to continue or not, otherwise I'm stringing her along. In most case when I show reluctance to go along with her plan she starts trying to manage me (shows her true colors so to speak) and I'm gone.
It depends on the reason/explanation and my intentions with the lady. At my age, I date to find someone for a long term relationship. While I want to enjoy a physical relationship, I don't want to date anyone who is promiscuous. If they are waiting because of sincerely held beliefs, then I will respect that.