Originally Posted by PhilosophicallyLost
He's very much of the belief that my choice to do so is immoral and he seems to find it be a very unhealthy relationship structure devoid of proper commitment.
I'd say the burden is on him to offer a reasoned argument as to why it would be immoral. And if he posits that monogamy is moral, offer a reasoned argument as to why it is.
Nobody--meaning you--has any obligation to humor his supposition that monogamy is moral and polyamory is immoral by beginning from that position and trying to refute it. He can do some real philosophical work and begin from neutral ground or play by himself; no need for you to enable his bad philosophy!
When speaking of various forms of non-monogamy...it ain't poly if you're just fucking around.
While polyamory, open relationships, and swinging are all distinctly different approaches to non-monogamy, they are not mutually exlusive. Folks can, and some do, engage in more than one of them at a time--and it's all good.