[Reminds him a lot of his sister reacting when he'd picked on her for still believing, as kids. Good thing he's actually not saying that, though. Quite the opposite.]

No, no, I'm not saying that, at all.

On my world, it's not... a regular thing, for adults to continue believing in Santa Claus. [Says the man who believes wholeheartedly in aliens. Childhood things are quite different, though, and for him childhood associations aren't usually happy.] But I saw that sleigh in the sky on Christmas Eve... that and those elves... it has to mean he's real. He exists.