I say it's time to get to know his dating and relationship history a better. It sounds like he knows more about yours than you do about his. Find out what happened with his last relationship and a little information about her. Wouldn't you hate to find out a month, two, or three down the road that he dates younger women short term? Has he ever been married? How many longer relationships has he been in? Does he want to settle down one day? Do you want to settle down?

Good luck!