S: That's mines.
Me: "Mine," honey, not "mines."
S: No, it's "mines."
Me: "Mine," not "mines."
S: I can say "mines."
Me: The correct way to say it is "mine."
S: I like saying "mines."
Me: I know you do.
S: I can say it however I want.
Me: That's true. You can say it however you want.
S: I say "mines."
Me: OK. Never mind...
(Even though her daddy is an English teacher, sometimes I just need to mind mines own business ; )