Monday on the way to religious education, I listened as Christopher informed his sister that there is positively no Tooth Fairy. Sarah, having a steadily growing stash of cash and no shortage of baby teeth, was none too pleased about this pronouncement.

"There is TOO a Tooth Fairy. Right, Mom?"

"No, there's not - it's always Mom and Dad, right Mom?"

Sigh. For a moment, I envied those parents who from Day One refuse to fan the flames of fiction in the hearts of their children. No Easter Bunny. No Santa. And no Tooth Fairy.

Sadly, I've never lost an opportunity to fan those particular flames. I was also mildly annoyed with Christopher for bursting his little sister's bubble like that. So I messed with him a little.

"So ... Christopher. How did you come to decide this? Was it something one of your classmates said?"

"Uh-huh. Josh said he peeked last night and saw his dad put the money under his pillow. He says it's always moms and dads. No fairies."

"Well, let's think about that for a moment. Doesn't Josh have an older brother, who might have told him about the Tooth Fairy?"

"Y-e-s..."

"So is it possible that the Tooth Fairy stopped coming to Josh's house because the Big Brother didn't believe in her any more, and the parents didn't want to spoil it for Josh?"

In the rearview mirror, Christopher's eyes furrowed as he thought about this one. "Well... but the last time I was at the dentist, I lost a tooth and the Tooth Fairy didn't come and give me money for that one."

"Well, that just means the Tooth Fairy sometimes makes mistakes. It doesn't prove she doesn't exist. I make mistakes, you make mistakes ... We all make mistakes sometimes."

Now his eyebrows were so furrowed they nearly touched. "Well..."

"Listen, Christopher. You don't have to believe in the story of the Tooth Fairy if you don't want to. You're a big kid now, and maybe you're too big for the idea of the Tooth Fairy. But you should know that if you spoil it for your little sister, the Tooth Fairy might just get so mad that she doesn't come around any more. And you wouldn' want THAT to happen, would you?"

That did it. Impromptu, in unison: "I BELIEVE IN THE TOOTH FAIRY!"

Okay, then.

Heidi Hess Saxton is a contributor to the AnnArbor.com Parenting channel, and founder of the "Extraordinary Moms Network," an online resource for adoptive, foster and special needs parents. You may reach her at heidi.hess.saxton@gmail.com