Many of our friends guessed that we were poly before we came out. Some were shocked but supportive. We haven't actually lost anyone, I don't think. But I'm actually sad right now because it appears that someone who we thought was supportive actually feels very negatively about our choice to be poly. So, I feel your dilemna.
Our group policy was, just act like you're not doing anything wrong. Don't make a big deal about it and enjoy life as it comes. We haven't had any big announcements, except when I just can't stand the suspense of not knowing if a certain person knows and I spill the beans. I'm not a good secret keeper.
No way I would ever tell my mom, or my family. My mom knows about poly from other friends of ours, and disapproves heartily. But she recently shocked me by revealing that she knows I'm Pagan and she didn't have a heart attack, so who knows? We do quietly insist to family and friends that Asha and Sunday and their children are important people in our lives and they're not going away.