Since I was actually in a live-in triad for a few years I figure I'll chime in on LK's question. Shel pretty much answered for our pairing.
Lady Kate wrote:
but what is that like?
It was like living with two people I love very much instead of one. It was also three incomes in the household instead of two, and an odd number to break ties when voting happened. And if one of us was deeply involved in something there were still two of us to hang out. And when one was upset to hugs are better than one.
Lady Kate wrote:
If there is sexual activity, must all parties be involved? If two of you want to have sex without the third, can you go into a bedroom and close the door and the third has to respect your privacy?
Every polyamorous/open relationship has its own rules. Ours was pretty fluid on the sex front. We each had our own room so if Gary and Julie wanted to get it on they went to one of their rooms. Or sometimes it was me and Gary. Or me and Julie. And sometimes it was all three of us. And when it was only two the third was generally OK with it. When he wasn't (it was generally Gary feeling left out) he'd knock on the door and we'd say 'come in' or 'girl time'.
Lady Kate wrote:
Does jealousy come into play?
Sure, but that's not the big deal everyone makes it out to be. Healthy relationships deal with negative emotions in the same way, no matter the number of participants. The person feeling the emotion says "I'm feeling this, and I don't like it. It happens when you do this thing. I'm working on my feelings because I know they are my responsibility, but could you be sensitive about it for a while?" and the other person says, "I'm sorry you're feeling that way. I'll do what I can to help you work through it."
Did you grow up with siblings? More than one? Once the sexual element is removed the dynamics are the same. Do parents decide not to have any more kids because there might be jealousy? Not usually... they expect that the children will learn to handle those feelings and be enriched by the experience. Why should adults be any less capable?
As Shel said, we're open but neither of us is currently involved with anyone else, and we're open to a live-in third, but we're not actively looking, and she'd have to be pretty damn special. We're happy as a couple, and it would be nice to have one more person to share that with. Any more questions? I don't mind talking about it, and you can message me if you have anything you don't want to be seen asking.