OK, I hate to break it to you guys, but as a former 18-21 year old female, almost all of those that go out with the 35+ crowd are missing their daddies. Not that there's anything WRONG with that, but I can count on one hand any girl I ever knew who went out with a much older man because she was truly attracted to him - physically or mentally.
I remember my Dad all excited because one of my friends was "hitting on him". She wanted to ride in his Porsche, lol!
But I strongly suggest you have a GREAT time while they're there! No point looking a gift horse in the mouth!