Kirk/Spock/Uhura trapped on an alien planet

[tristesses.livejournal.com]

Hi guys! I've been searching for a certain fic for ages, but I haven't had any luck, so I thought I'd drop by here and ask!

What I remember:

1. They were stuck for some reason on an alien planet where polyamory was the norm.
2. They had to pretend to be together to blend in, and eventually actually fell in love.
3. I think it started out as K/S, but they might have all been single.
4. They were stuck there for a very long time - years, maybe.

Any ideas?

And TIA for your help!