I'm 50 and find that the men I go out with assume they are going to pay for the check. I'm always prepared to pay my half or the whole check though and most of the time, offer to do so. When the check is brought, I usually bring out my wallet and if not told to put it away, will lay a bill that is at least half on the check.
However, as I said, I rarely have paid on a date. In fact, one time, after having watched an episode of Dr. Phil and deciding I needed to assert myself in making a statement, that I was not looking for a free ride but would be a partner in the arrangement, I insisted on paying the bill, which was less than $20. The man I was with was very upset, it was a first date, and there was not a second.