Disclaimer: I do not own Avatar or Fullmetal Alchemist. Just laying that out there right now.
The silence in the hallway outside the royal bedchambers is tense. No one speaks. This is because Aang cannot say anything nice to Zuko since Katara finally dumped him and hooked up with Zuko. Sokka won't speak to either of them because then he'd either be incinerated by Zuko or Aang would accuse him of taking sides. Either way, he's pulling the protective big bother act and glaring at Zuko for doing this to his little sister.
Toph stays quiet because she's asleep.
Zuko is too busy glaring at the door to his room in an attempt to cover up the nervousness he feels. He thinks that if he opens his mouth just once, he'll start blabbering like an idiot. He's already scared to death Katara will make good on her threat to have him castrated.
The door opens and a tired but happy woman emerges. "My lord, you may come in now."
Sokka and Aang jump up with him as Zuko begins walking toward the door. The woman stops the other two, though. "The Fire Lord will be the first to see the Fire Lady and their child."
Privately, Zuko's inner sadist cackles maniacally as his brother-in-law and the Avatar wilt visibly. Toph does the laughing for him, though.
Forgetting the clowns outside his chambers, Zuko approaches the bed. There lays Katara, beautiful Katara, tired, but happy. She smiles when she sees him and beckons to him to sit next to her. In her arms is their newborn child, a son, or so the woman said.
"He's beautiful," Zuko whispers. "You're beautiful."
Katara chuckles. "I don't feel beautiful." She motions to the baby in her arms. "What should we name him?"
Zuko shook his head. "You should name him. You did all the work."
But Katara is insistent, and finally, after several minutes of arguing and subsequent deliberation, Zuko ccomes up with a name for their little boy.
"His name is Roy."
And that, ladies and gentlemen, is how Roy Mustang, the Flame Alchemist, came to be.
AN: The idea and the title were inspired by a conversation I just had with the wonderful Zelha, in which we laughed over Roy being Zuko and Katara's lovechild. Hope you enjoyed it. I know I enjoyed laughing at it as I wrote it.
My thanks to Zelha for the inspiration and the title!