The really sad thing about it was, Zuko really did love Katara. Maybe not the way his waterbending wife loved him, the way a wife was supposed to love her husband and the way a husband was supposed to love his wife, but he did love her. It was why he felt so guilty about constantly sleeping with Mai.

When it was discovered on his third birthday that Kuzon, crown prince of the Fire Nation and son of Fire Lady Katara, was an airbender, Zuko felt less guilty.