Lucy: We’re going back to our house Max
Max: MY house?
Lucy: No, OUR house.
Max: MY house!
Lucy: No, OUR HOUSE
Max: MY house!
Lucy: Mommy, when there are two people and they are talking and one asks “is this your house” don’t you answer “yes, this is OUR house?”
Me: Well, yes, when you are referring to two people living in the same house you would use “our” and when it is only one person living in the house you would use “my”
Lucy: Right, Max you are supposed to say OUR house Ok?
Max: OUR house?
Lucy: Right, OUR house.

I’m so proud, I shed a small tear.