Could the jig be up so soon?

My kids are growing up and I'm a little melancholy about that statement of fact. Yesterday afternoon when we were at the pool, my youngest was having his swim lesson while the oldest was working on homework. I was making small talk while he was getting his notebook out, etc. Here's sort of how the conversation went down...

Me: So are you excited about Christmas coming up?
Him: Yes.

Me: Do you want to go visit Santa at one of the malls this year?
Him: No, I don't think so.

Me: Why not?
Him: I think I might be getting too old for that.

I'm nervous and dying to know what he's thinking at this point!

Me: You're too old? Don't you believe in Santa?
Him: Oh, I believe, but I just think I'm too old to sit on his knee.

Me: Hmmm... Do you and your friends at school talk about Christmas and Santa?
Him: Not really.

Him: I'm not so sure I believe in the Tooth Fairy anymore.
Me: What? Why not?

Him: I'm just thinking the next time I lose a tooth, I'm going to check the amount of money you have in your wallet before I go to bed, and then I'll check the amount of money in your wallet again the next morning.
Me: (About to laugh) So you think I'm the Tooth Fairy?

Him: Maybe... I'm just sayin' maybe.
Me: I'm not saying you're right, but what if I am? Would you keep it to yourself or would you share that information with other people? (I'm hoping he won't spill the beans to his younger brother.)

Him: I'd tell the world!
Me: (Mortified) Why would you do that?

Him: Because I'd want other people to know the Tooth Fairy and maybe even the Easter Bunny aren't real.
Me: (Sadly) But think about how much fun you've had believing in them all these years. You wouldn't want to ruin anyone else's fun, would you?

Him: Well... I don't know.

The conversation ended and I'm thinking the jig is up, folks! The smarty-britches 11-year-old has our number and I'm betting the younger brother calls our bluff soon enough. Doggone it! I've been dreading this day for so long, the day when innocence and childhood fantasy come to an end and the realization sets in that your parents have been lying to you all your life. I can only hope we have helped give our kids some very special memories of these years. Maybe our oldest will keep his thoughts and opinions to himself and allow his younger brother to believe for a little while longer.