Good thread, Victoria, gives me a chance to whine.
6-7 years ago I had this (female) friend, we were brilliant together, you know, the sort of friendship when you finish each other's sentences and always know exactly how the other one is feeling. Unfortunately, she was after a girl who wasn't even into women but kept stringing my friend along with false promises. After a couple of years I did manage to seduce her (my friend) at last but she soon decided that she'd save herself for her evil idol and we became friends again - for half a year or so till she left the country to follow her evil idol. The last I heard of her, they did get together for a short while and then she was dumped (of course!).
After that I found another buddy - through work. Sex was great, we would even throw in an occasional client (bad idea. Men think their ultimate fantasy is girl on girl, but when they get it for real and see that no one in bed is interested in them, they get pissed off) but after a while I broke off the friendship - sex had nothing to do with it, I'd still have it any day with her - but as a friend she was unreliable beyond belief.
So I'm genuinely jealous of those for whom it does work out.