It's an accident. It really, truly is. Zuko was correcting a fire kick with a laugh, watching Aang's face contort with frustration. It wasn't that he wasn't flexible enough- he just tended to over or undercompensate with the motion, leaving him doing the splits sideways or kicking gravel.
"It's alright," Zuko says, trying to be reassuring. "It's not easy to get the angle on this one right. Lu Ten used to-"
And he stops.
And he looks away.
And he feels horribly guilty.
"Lu Ten?" Aang repeats, brow crinkling. "Was that your firebending teacher?"
"No."
"Oh."
Zuko can tell the curtness to his tone hurts, even if he doesn't intend for it to. He sighs. "He was- is- my cousin."
"Oh," said Aang, differently this time.
"He used to help me with my stance. He said I looked like a baby turtle-duck trying to fly when I'd do this one- swinging blindly around and hoping it'd stick."
Aang sets both feet down on the solid stone. "You've never mentioned him before."
"It's rude," he says with a shrug. "To Uncle."
"Is he-"
"Yup."
"Oh," he says a third time. Aang considers this new information for a moment. "I know the Fire Nation prefers to grieve silently. It's a little different for everybody, you know?"
"I know," Zuko answers, thinking to that time he'd almost lost his shit at an Earth Kingdom wake. "It's not like you're exactly talkative about your family, either."
It's Aang's turn to shrug, huffing out a chuckle. "Oh, I never knew who my family was. Probably traders or merchants, or other nomadic people. The monks always said that, to properly detach, we can't have ties like that to this plane." Aang pauses, then admits, a tad shamefully, "I always kind of hoped Monk Gyatso and I were connected. Not by blood, but... maybe old reincarnations."
"Huh." It's a far cry from Zuko's upbringing, where blood had meant everything, but it feels sad in its own way. Maybe his dad was a dick, but it was still kind of nice to have a name and face. And, as much as he hated to admit it, he did love Azula, and she loved him too- in her twisted way. "So, no one knows who is the child of who?"
"Pretty much. The Council of Elders kept some basic records, so no incest or anything that could harm the future generations, but it didn't matter. They always said our mother was the sky and our father was the ground. If we fell from one, the other would catch us."
"Sounds like they were giving you neurosis young."
Aang laughs. It's full-bellied, like that insinuating the monks had daddy issues with dirt was absolutely priceless. "I guess you could say that, yeah."
Author's Note: I did this for a drabble prompt on Tumblr and liked it, so I figure I'll cross-post it!
-Mandaree1