Strictly speaking, polygamy means a man being married to more than one woman. Since that is illegal in the USA, and you want to breed with your unicorn, have you considered how to legally and financially protect your hypothetical baby mama?
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
me: Mags, 58, living with:
miss pixi, 37, who is dating (NRE):
my bf: Ginger, 61, married to:
Robin, 60 (mono)
and dating (NRE): Carla and David, married couple, early 40s