An open or polygamous relationship definetely wouldn't work out for me. Jealousy, jealousy, jealousy...I have a problem with that
I just don't think it would work out for me. What happens if after some time with your fuck buddies you develop feelings? I think that's natural ;p
I don't think I would let my partner have sex with somebody else if we were in a monogamous relationship either if he needed it...I mean, it wouldn't be monogamous then, right? ;p I don't think I could live with that.
But I guess it also depends on how a person views sex. To some people it doesn't mean anything, itt's just sex. But well...like I said, I'd be too jealous ;p