Take him to Jack of the Wood and sit him down with a big beer and tell him you love him. Then his buddies show up (because you planned it that way) and everyone has a fun time. Better if there's a bluegrass band playing that night. You drive so he can imbibe a bit (if he likes that, of course).

Also, what everyone else suggested are all good ideas, too.

My SO surprised me once by saying that he just wanted me to pay more attention to him. I thought I was getting in his way. I was happy to oblige.