I've been looking for this particular story that I originally read once upon a time on AFF.net, but it no longer seems to be there. As unhelpful as it is, (I know, I know!) title and author have been lost to my memory. Looking through other archives and Google-fu have both failed me, and it never got saved to my computer.
It's a Human AU where Spike and Xander are brothers (or half-brothers, maybe) whose parents got divorced when the boys are very young, and each parent took one child to raise; Xander in California and Spike in England (e.g. "The Parent Trap" movie). However, Spike and Xander both still remember each other, and when they get old enough they manage to track each other down.
Both miss the brother that they vaguely recall, but after getting reunited each one finds himself having feelings that are not so brotherly towards the other. Forbidden attraction! Gay incest! Yadda yadda yadda... 'Nuff said.
I think they do finally end up together, but I'm not positive. I've been looking for this story for over two years and would be undyingly grateful if someone knows of it. Pretty please?