He thought I needed a lesson in respect, so he challenged me to an Agni Kai. I refused to to fight, which is apparently more deplorable than losing.

[ zuko lets her hand go and jerks away from her, repressed anger and turmoil bubbling to the surface much like it had in the catacombs beneath the palace when he confronted his father. ]

I was thirteen! What sort of father tells their son to fight him, just because he spoke out of turn? What sort of father puts a fistful of flames in his face for refusing to do so? Who does that!?