In the "Nightmares and Daydreams" Zuko was like:
"Do you think you can find a fresh fruit tart for the lady?"
And throughout the whole series we don't see Zuko calling any other girl like this.
So, that somehow convinced me and canonized for me that later, in the future, when they're married, Fire Lord Zuko is calling his wife "My lady"/"M'lady". I mean, she is the Fire Lady, no?
And every time Zuko gets all sappy and flirty, and "How is my (Fire) Lady?" or "Anything for my lady", the gaang makes vomiting sounds in the background.
P.S. Mai tells him to stop but secretly she likes it.













