Sometimes my kids and I call each other “sir

Sometimes my kids and I call each other “sir.”

I will say to my child, “Sir, you cannot do that. Sir, you cannot park there,” when they sit where they should not or do something they are not supposed to do. If they get up at night, I will say, “Sir, you cannot be up at night.”

And they return the favor. They will ask me, “Sir, may I please do this? Sir, may I please do that?”

We all find it funny to be overly polite and formal with each other.