AU Fic Prompt (stolen from someone else's meme)

Saw an interesting prompt on another person's meme, actually wrote something for once (gasp!).  Cut for mpreg and grouchy firebenders.

Edit- ack, forgot to include the prompt itself.  It goes as follows:  Ozai mpreg. Zuko is Ozai's son, but Ozai isn't his father. Zhao is. Fury.

( When the Fire Nation’s second prince starts heaving over the rails... )