December's Children Puns

I teach high school math. The other day, December 1st, one of my students was looking at the date he wrote down on the paper he was about to turn in and said, "Hey, today's December!"

And I replied, "Yeah, and tomorrow's December, too."

The class started groaning at my bad joke, but I didn't even realize I had said a pun until they started groaning! I don't even have children, but the dad in me must already be growing.