I never really understand ‘it’s not natural’ as an argument against monogamy.
I mean, if you think monogamy is a repressive, malfunctional relic of an institution that you want no part of, then more power to you. But I don’t know how ‘it’s not natural’ works as an argument. We’re out here riding segways, messing with the thermostat and thoroughly cooking deer meat. We decided nature was a shitty place to live quite some time ago.