Yes, Sir

I was downstairs checking email while Kaden and Brynn were actually playing nicely for a minute. Here is their conversation
K: "That's my marble set."
B: "My marble set."
K: "No, It's my marble set."
B: "MY marble set."
This goes on at least ten times. It is not a yelling match either.
K: "It is my marble set. Say 'Yes, Sir.'"
B: "My Marble set."
K: "It is my marble set. Say 'Yes, Sir.'"
B: "Marble Set?"
K: "Brynn it is my marble set. Do you understand? Say 'Yes, Sir.'"
B: Yes, Sir.

I guess Kaden is trying to teach respect and manners to Brynn.