No problem, and yes, it’s only polite to be consulted about something. My husband is a big fan of what he calls spontaniety. I call it lack of planning. Obviously, either point of view taken to the extreme is nuts.
When we were first dating I was still performing. On the closing weekend of Swan Lake, he had a tremendous surprise for me. He picked me up after the last performance, and we drove through the night into the wilds of northern New York (near where I was born) to do–guess what–climb Mount Marcy! His thought was to make the trailhead by daybreak, because (like your husband told you) “You just gotta see this!” I slept most of the way in the car (hadn’t even showered after the performance, and the closest thing I had to appropriate footwear was a pair of ratty sneakers, complete with slashes in the vamps for my ballerina bunions!) Big black flies were everywhere, and with dried on sweat, I was a smorgasbord for them.
He woke me up when we got to the trailhead, got out a huge backpack that looked like you could survive on the contents for a couple of weeks, and said, “Let’s go.” I said, “Go where?” He pointed up.
I laughed weakly. Then I pointed to my blistered feet. “You mean with these?”
He got the point. We got back in the car and headed to a diner, then headed to a motel to crash. A few hours later, we went into Lake Placid to get me a decent pair of hiking boots and a lot of bandaids.
Sometimes it’s just a lack of communication. But heck, it sounds like you have a great trip planned, anyways.
Enjoy the dunes, and everything else. And judging from the pictures of that dune, better do some stationary bicycling before you even think of climbing it! And wear good boots with ankle support.