i have to say that if an in-character GAY Zuko was to be romantically interested in any other boy in the show, it would certainly be Aang.
He seems to be mostly annoyed by Sokka, but they still have a great friendship. In fact, friendship between them started because they both share a feeling of inherent duty to those around them, and a need to regain their honor when they felt they've lost it. In the movie, this pattern follows. Zuko seems annoyed with Sokka most of the time, but still likes him a lot. There's even a joke about Zuko telling Sokka he needs to "accept his death with honor", because they're about to go into battle and Sokka is afraid. If anything, Zuko and Sokka have a the brotherly relationship, where Zuko is a gives advice and is a male role model for Sokka. I could also get into the fact that I think Sokka would not be equipped to deal with the emotional support Zuko needs, but this is more my own speculation and not entirely based in canon.
As for Jet, Zuko was down to help him when he saw the injustice regarding their meals on the boat to Ba Sing Se, but when Jet asks Zuko to join the freedom fighters, Zuko refuses. To be quite honest, Zuko is entirely uninterested in Jet as a person. He doesn't care for him at all, while Jet projects himself and his past onto Zuko. Jet, to me, has this "lone wolf" complex, and Zuko suffers from that, but he just completed an entire arc in Book 2 where he rejects help from Iroh and then realizes he needs Iroh's help. I see the appeal of "toxic Jetko" I guess, but Jetko only comes off as one-sided to me, and I don't really like stories where Zuko never heals or gets better personally (it completely defeats the purpose of his character to me).
AFAIK he never interacts with any other boy else his age. If we're counting the movie, he might have had the hots for Tagah before getting BTFOd by him.
now i don't ship them as they are in the show, but here is a bunch of propaganda for the foundation of what could be when they're adults, or in an au where they're aged together.



















