He considers this.
"Does he ever stop?" he says.
"Oh, yes," I say. "I don't get a stocking any more."
"Not even a small one?"
"Not even a small one."
It's the Terry's Chocolate Orange I miss most. I know I could just go out and buy one. But it's not the same. It's not the same as when Santa brings one.
"Well maybe," says my son thoughtfully, "I could just leave out an empty stocking, just in case, and see if the sleigh stops over our house?"
Good try, I think. But I'm not going to let him off that easily.
"Well, obviously it's going to stop over our house," I say. "There are other people living here who aren't 18 yet."
I imagine the reindeer hesitating in the starry night sky.
"Is 18 the cut-off, then?" he says.
"I don't know," I say. "It should be, don't you think? I mean, at 18 you're an adult. You can drink in a pub. You can vote."
He looks at me. I wonder how he's going to reason his way out of this one.
"But you're not sure?" he says.
There's a small pause. "From what I hear," I say, trying another tack, "Father Christmas doesn't have a lot of spare cash this year. Because of the recession. So there might be economies all round."
"It's just the chocolate I want," says my grown-up son. "Just the chocolate, really."
What can I say? I know the feeling.