In its essential core, peace is an ideology, much like perfectionism. It's idealistic but is it realistic on a societal level? No, unless the population is small and the differences among people are less varied.
Aside from morale and general consensus of what constitutes a healthy modern relationship, open relationships are often questioned whether or not they're healthy for both consenting adults and the children involved. I can only assume based on the information I've observed with polygamous...
There will always be inequality in a world without balance. Humanity in general seem to find it hard coming into terms with a balanced and peaceful nature some of us want in our lives. Some may argue that the nature of suffering interferes with balance.