Open relationships can work. What really gets me going is people who say they dont work when they've never experienced one before. I agree that most people cant stand the idea of imagining their partners with someone else. I'm not encouraging the idea of open relationships, but I will say that they do work if you set boundaries and respect them. Ultimately, whether you have a monogamous or open relationship, it will not work unless you respect each other and have open communication. Simple as that.