Frolic on the sand at a local beach. Whether you live by an ocean or a lake, take a blanket and a picnic lunch for a guaranteed fun time. Play touch football near the water, and talk about your favorite summer vacation trips. If you're really getting along, let him reapply sunscreen to your back later in the day.
Get lost together in a corn maze. It might take hours for you to find your way through, but who cares! After you get out, warm him up with a cup of hot cider and some cuddling. Check the Corn Maze Directory at cornmazedir.com for one in your area.