All right, now that it is no longer a WIP, it is imperative that EVERYONE IN THE SHERLOCK FANDOM reads
A Cure For Boredom by
emmagrant01 (Sherlock/John, as well as loooots of other porny situations; it well and truly earns its NC-17 rating).
Why?
Well, because it will very likely be hotter than every other piece of erotica you've read.
And because it is such a fucking amazing, mind-blowing, breathtaking exploration of the subtleties of the dynamic between Sherlock and John and includes so much extremely tightly written, well-worded, smart, nuanced discussion of sexuality that it's almost like, I DON'T EVEN KNOW, an unbelievably hot and lyrically written anthropological study on human sexuality.
I can't with this fic, you just have to read it. It owns me.
Make sure you have, I estimate, about three hours available for reading and then about nine hours for hyperventilating and YES MAYBE ALSO BEING A LOT AROUSED. I regret nothing.
Do it. Dooooooo iiiiiiiiit.