Before any non-monogamists go nuts on me; cool your jets. I'm bisexual. I've been with the same guy for almost 5 years now. I occasionally fool around with girls. He knows about it. He's fine with it. We don't have a traditional relationship. If he were ever uncomfortable with me doing what I do, I'd quit and never be with anyone but him ever again. I rarely ever have sex or fool around with anyone but him anymore anyway. When it happens, it's usually not planned. I don't have a very active interest in looking for a girl to play around with but if the opportunity is there and it happens? As long as he's okay with it and she's okay with it just being about sex; swell.
I just get annoyed with how many people spend so much time fighting for their lifestyle choices not to be judged negatively and looked down upon just because it's different yet in the process of fighting for that, they're negatively judging and putting down other people's lifestyle. You don't need to throw out divorce statistics, reasons why monogamy isn't sensible, tossing out statistics on why people cheat and on and on and on about how it doesn't work or how it's outdated, etc. It's insulting to tell someone in a happily monogamous relationship that they're jealous of you because you're open and secure enough to have other partners in your life and that they just wish they could have what you do. Not everyone wants that. It's like when someone against your open lifestyle tells you that you're just self-centered and attention seeking and that's the reason why you look for partners outside your relationship. Or that you're insecure and that you need to be validated by as many people as possible to feel worthwhile. While both statements can be true for some people on both sides, they're not true for everyone. You can support your lifestyle and your choices without tearing down another one to make your point. It puts you on the same level as the people you're "defending" yourself against once you start judging, trashing and negatively tearing them down for their choices.
You can't expect people to be accepting of you as you scoff at them, no matter what the subject is.