Katara always thought that there were so many more romantic moments Zuko could have chosen to kiss her for the first time.
He could have made a cautious but tender overture on one of those moonlit nights on Ember Island, when they had stayed awake while all the others slept, speaking in hushed whispers of the past and the future. She might have cried if he had, all her confusing feelings for him dragged to the surface, back then when it had seemed like anything might happen to them. He would have been mortified, probably tripped over his words to apologize, and she would have had to reassure him he hadn't done anything wrong. But then there might have been a conversation more about the future than the past, and promises of things to come, when the time was right, the circumstances better.
But he hadn't done that.
He could have passionately embraced her in the aftermath of the comet's passage, when they were both dizzy with relief and heady with victory. She had already been crying then anyway, so in awe of him and everything he had done that day. She would have kissed him back without hesitation, that brave and selfless fool who had risked everything for her. There had still been so much unresolved at that point, but the one thing she had known was that they had both survived, because they were together. That had been its own prize, worth all her tears, though perhaps the kiss would have made it that much sweeter.
But he hadn't done that, either.
He could have pressed his lips to hers in that moment of impulsive happiness when they had danced together at the festival celebrating the anniversary of the war's end. It might have been a bit public, with all the other revelers around them, but she liked to think they would have all been too caught up in their own dancing and laughter to notice. It would have been a quick kiss, and she would have smiled at him after, and they would have gone on with the dance, perhaps with just a bit more spring in their steps. And then maybe later on the two of them would have found a more private place, to follow up on this new development more thoroughly.
But that was also not what he had done. So while all of those moments were memories Katara would cherish, they did not bear the particular distinction of being the moment of their first kiss.
What actually happened was far less dramatic. They were going over notes for an upcoming trade summit. Zuko asked her to pass him the scroll containing the report on that year's rice harvest. She handed it to him, he thanked her perfunctorily, and she smiled. Then he leaned forward, across the corner of the desk where she was sitting adjacent to him, and placed the softest kiss just at the corner of her mouth. His lips were warm and dry, and she thought at first he must have been aiming for her cheek and missed.
But when he drew back and met her eye, she was quickly disabused of that notion. "You don't know how many times I've wanted to do that," he said.
It was Katara's turn to lean in. Her lips met his full on, more deliberate but just as gentle, their second kiss following soon on the first, as if to make up for lost time. "You don't know how many times I've wished you had."