Okay, normally I stalk, but I've got a think it two to say about polyamory.
I, myself, am polyamorous. However, I only have one boyfriend and I plan on keeping it that way because, from they way he has acted, he is not poly. I love this man, and we have worked to have a good relationship, and I'm not going to force him into anything he doesn't want.
Everything comes down to consent. I myself would never take on another partner without consent from any and all current partners, simply to make sure everyone can get along. In a polyamorous relationship, you cannot just claim to be in love with someone and take them as a partner without the approval of others, because this breeds jealously. Hell, jealously will be able to show up even if everyone does agree to the new partner. The key to a healthy polyamorous relationship is open communication, just like any other. You must communicate how you feel, and allow the group to help you with what is happening.
Yes, many claim polyamory to try to get away with cheating. However, it is still technically cheating if you do not discuss with your current partner taking up another or even just telling them. I know this is not a lifestyle for everyone, and I think it disgusting that people try to force it on others. If you really love someone, you'll respect their decisions, even if you don't like it.
So, yeah. I'm sorry if it's not really cohesive, I'm just spitting out words now.