Just wanted to add my own little success story. I'm in a cute little hetero MFM poly-fi V -- just blogged about it
if you're interested -- and couldn't be happier. We had some rough times in our early years together, but we gradually learned how to live with each other in peace and harmony.
Today we live together in a lovely new apartment unit. Each of the two guys has his own bedroom, and Lady Hinge alternates nights between us. I have a little "bed and bath" kingdom where I spend most of my time, with a generous-sized window looking out at the trees and sheltered skies of Washington (near Seattle). My favorite older brother lives nearby and we can see him often now, along with his wife, her daughter, and her daughter's boyfriend. We get along with them splendidly and love it here. Most of our relatives live in Utah and Michigan but that's okay; we're far removed from the family politics.
For me the gift of privacy is what opened the doors to contented communal living. Just knowing I have a "place to hide" if things get heated is exactly what keeps things from getting heated and makes me feel happy to share my time and company with my two companions. Sure I'm usually tucked away in my bedroom, but no longer does it make me nervous to "come out and play." For those moving in together, I strongly recommend making provisions for everyone's privacy.
We've been handfasted since mid-2009 and together as a V since early-2006. Our first few years together saw much paranoia on my part, afraid that Brother-Husband would veto me out of the family. I imagine that he in turn was concerned that I -- the "new and shiny" -- would nudge him out of the picture. We just had to find our comfort zone with each other, and establishing privacy, for me at least, was a necessary step in that process.
We're open to becoming an N or M or what have you, but aren't looking and like what we have already. We don't have sex outside our three-person circle, a rule that we don't mind obeying. Some people would need a lot more polyamorous freedom. We're rather conservative compared to the "average polyamorous demographic," but that's okay because it works well for us.
So for those wondering if a poly tale can have a happy ending: Yes it can. True, not all poly tales will end happily, but this one sure has (though of course it's not the "end" by any means).
Glad to answer any questions if anyone has any.