Triplese7en: AU where the Fire Nation is not only fine but rejoicing in hearing about Azula and Zuko's relationship... but the gaang isn't ok with it.
I can see Azula being like "Who cares about the opinions of those stupid foreigners?" and just basking on the satisfaction that everyone in the only country that matters is super thrilled… then trying to win the Gaang over because Zuzu is sad that his friends don't support their love and she doesn't like seeing her big brother upset (except when she's the one who made him miserable - intentionally).
She'll be on her best behavior around them to make them realize she's the perfect woman for Zuzu… and then once it's been at least two years since they accepted their relationship, she'll fuck Zuzu on each of their beds as retaliation for them having been against it in the first place.