codependence.PP has a tough choice to make. Dan tries to make it sound like it's an easy one, a lifestyle choice, but he's wrong. Many therapists would agree that giving up who we are to make someone happy is not a very healthy relationship strategy. At some point it sounds a lot like
Over the last 15 years I've met many, many polyamorous people for whom being polyamorous is to them about a lot more than what (or whom!) they do. They say emphatically that it's about who they are. Many tried to live by mainstream society's monogamy rules because they thought they had to, but it chafed - a lot. Many always felt like they were different and like they were the only ones who saw relationships differently. We still have people come into our community who are delighted and relieved to have discovered they weren't alone after all.
Is polyamory a sexual orientation? Some will insist that it is not as to the traditional meaning of it. Yet many polyamorists express themselves differently sexually, i.e. with more than one person at a time. If not sexual orientation, then sexual relationship orientation or sexual relationship identity - that's how I refer to it, and I've done so for some years now.
I expect that this point will be made much more frequently in the future as research under way now gives us more scientific insight into such questions. In the meantime, I hope Dan catches up soon because his advice basically says to PP that his identity isn't valid. I have to wonder how Dan would feel if someone told him his identity isn't valid.