"Okay, Jet, I'll go with you."
"No! No. You go up, by yourself. So you don't see me taking the ornaments off the tree."
"You go up to my room. I'll play ornaments and put 'em back. Don't worry."
We'd had a very long discussion, while decorating the tree, that the ornaments weren't for playing with, like toys.
But there was one ornament of a little man on a bike with wings that Genevieve had given Jet when he was a baby that he was dying to play with. We finally figured out that it was just the one, and gave it to him for supervised play. He was great with it, and very gentle after we described how fragile it was.