The Course of Honour - Avoliot
I had forgotten that Archive of Our Own includes original works as well as fanfic. I saw a recommendation for this sometime last night, and look, I'm already two thirds of the way through. Whee! If the author had other original works available, I would probably have downloaded them by now.
I mean, it's not perfect. If I didn't enjoy the main characters so much, there are things that would probably irk me more. It's a sci-fi romance that's extremely light on the world-buliding - it's easy to forget about the sci-fi aspect until the characters talk about data coins and flybugs and such. Also, I've noticed a few writing tics, like the tendency for characters to say "What" (no question mark) during scenes that call for them to be amusingly stunned. And the main characters spend a lot of time trying to read each other and yet are incredibly bad at it.
But I'm still enjoying myself. Even though I'm currently very frustrated with one of the main characters.
(Oh, and link here if you're curious and don't want to search. It's m/m sci-fi romance with political marriage and a bit of intrigue.)