MILV retelling, either book!verse or Granada!verse H/W slash

[wonapalei.livejournal.com]

I've been trying for a week to find this fic. It's a retelling of the Charles Augustus Milverton case, set in the Victorian era with Holmes and Watson already in an established relationship. Holmes is very secretive about his client to Watson, not trusting him with any information, and eventually, Watson comes to the conclusion that Milverton is blackmailing Holmes with proof that Holmes has another lover that he's seeing on the side--thereby not only being able to expose him as a homosexual, but also to destroy his relationship with Watson. Watson actually packs up and walks out; Holmes chases him down before the cab can pull away, and...well, I won't continue it for the sake of spoilers.

Help?

ETA: Found by yawmin, it's Splendid Night by Katie Forsythe.