"Are you a grown up"

SO my youngest son asked me yesterday if I was a grown up?

We had gotten done with skiing and were at my parents about to have some dinner. I was taking a break in the upstairs bedroom. Brady was staring at the electric train set that is set up on the floor.

There is a rule that kids can't play with the train unless there is a grownup present.

Apparently, according to Brayden, that is an old person not mommy, like grandma and grandpa old. (he actually said this later at dinner when I recounted the story to my parents)

So I had a fun giggle and told him that yes I am a grown up and he can play with the train. Then what was even funnier is he plugged in the train and then sat in the middle rearranging the blocks from the tunnel formation into a station while he waited for his brother to finish his bath. He won't play with it without him.