My first thought was bowling...then I peeked at other answers! WOW I see it's already there. But seriously we have so much fun going bowling...we are both competitive and heckle each other all the time. We laugh when the other one makes a gutter ball, we joke how a strike is a lucky!
Then I thought about going window shopping at the Plaza...already said.
How about the going for an afternoon date to the Nelson? We've also gone an wondered around a book store...talking about books we've read, comparing books we've read...giving each other ideas for new books.
Go to Powell Gardens, or the Overland Park Arboretum & Botanical Gardens, take the kids to Deanna Rose...Go to to a Tbones game, Royals Game, Sporting KC, etc.
Make a list of new restaurants you want to try...
Make a list of places you want to go things you want to do...
Make each list separately, but them up per restaurant, things to do...different piles put them in separate bags. One of you reaches into the bag pulls out the restaurant, one of you reaches in and pulls out the event.
For the restaurant you don't have to choose days/weeks in advance you can pull that out the day of.