Help! What do I tell a 40-something year old that hasn't learned to look and not touch?

We recently moved into a new town where we already had friends who had moved from the old town. One of them was rarely at our old house but now frequently visits at the new. We've discovered that he picks up anything and everything to inspect it. He doesn't appear to understand that some items are fragile, or not finished appropriately to be protected from oily finger prints, or maybe not sturdy enough to be handled, or old, or valuable. . . or . . . or . . . or.

He hasn't actually climbed on anything but he'll reach onto high shelves to pick up a piece of fragile carving to look at it more closely. Being 6' tall, most shelves are within his reach. Yesterday, he rolled around on the carpeted floor of the stair landing a large carved wood owl that at least was strong enough to take the mauling but he could have simply knelt down. He's an incredibly curious guy and I do appreciate his desire for knowledge, but I was taught to look and not touch. If the homeowner picked it up and handed it to me, then and then only was it acceptable to handle it.

How do I tell a grown man to keep his friggin' hands in his pockets? I'm afraid I'm going to really let out a sharp rebuke one of these days after we finally unpack all of our art work. I need to know what to say before I give him a tongue lashing out of impatience.

One bright note is that unlike an infant he doesn't immediately put everything in his mouth!