We moved across the country close to when we were actively deciding to be poly (versus just conversing and researching about it). When we got to our new home, we started going to poly/open events which is where we met a majority of our current friends - no need to come out there! lol
I told my parents in person when they were here for a visit. It was awkward, but they weren't surprised. They seem to think it's a phase and that I will grow out of it. We don't talk about it, and since I haven't had any serious relationship last long enough to really mentions... I'm okay with that. Hubby also told his mom, who has opted not to tell his dad until the need arises. They also don't really talk about it, although when he mentions Lady, she tells him that she's "glad he's happy." Which I think is cute.
My one sibling knew because we spent a lot of time with her and her family. She is also exploring polyamory and has had an open relationship for quite a while (not as long as I have, but long enough that we have had multiple conversations). It's nice to know she has my back and that if I really need her, she's there. We've never been that close so it is one of the few things that really bonds us.
Hubby has told a few of his coworkers that we are open but hasn't gotten too specific. They know we both spend time with other people, and that it is more intimate than most would want their spouses participating in - which is why the conversation came up (they were asking how he felt about me constantly spending time with Boy and Doomed and asking how I felt about him spending a ton of time with Lady). They will know more specifics after a party we're throwing soon when they meet our poly friends.
I have mentioned polyamory at work a few times - specifically when Lady was going through a breakup with her now ex-fiance. My coworkers give me funny looks when I tell them Boy spent the night and things like that, but I don't feel the need to give them details unless they ask. A few of them may be coming to the upcoming party as well, so they may have more info than they need/want after that.