What's Your Kryptonite?

Apparently Will's kryptonite is rubber stamps.... ???

He's in this mommy and me class that is a blast. The teacher does a good job of helping the kids learn to clean up after themselves and share with one another, but she sets up all these great stations of a ball pit, tube to crawl through, obstacle courses, giant blocks, stuffed animals, etc. Will has a blast wandering around, playing with other kids and laying in the ball pit. At the end of the class the teacher sits on the floor and the kids run up and get a stamp on their hand, or hands...arms, belly, whatever they want.

The first class, I made the mistake of helping clean up and let Will wander over on his own. He didn't know what it was about and walked right on up to the teacher. She stamped both his arms and he turned to me to give the the saddest, most pathetic face ever, and cried. Since then, I've tried to show him that it's ok and I get one myself... That didn't work. He turned and cried in my arms.

Today, I sat him on my lap and we watched ALL of the other kids get their stamps. They're giggling, smiling, running up excitedly to get their stamps. Some even lift up their shirts so she can stamp their bellies. Too cute! The second the teacher looked in Will's direction with the stamp in her hand, he lost it.

He's never acted this way with anything, so I find it weird and kind of funny. Do your kids (or you) have something that totally sets them off?