Polyfidelity is just one subset of polyamory. Restricting yourself to a closed group of two or more partners is not what makes one poly. There are swingers who restrict themselves to sex only with another particular couple or group, and won't sleep with outsiders. They are not poly, even though they have a closed group of partners.
What separates the polys from the people in open relationships is that poly people are open to a wider range of emotional possibilities in their relationships. I have heard of people in open relationships dumping partners because "it got too serious," meaning the other partner fell in love with them. If they want to keep things light, then fine, but it ain't polyamory.
Poly-amory = many loves. Or the openness to having such. It's that simple.
Last edited by scarletzinnia; 01-09-2014 at 09:53 PM.