Cindie, thats an interesting viewpoint which is part of the reason I posed the question. Although I'm thinking now that I may have put it in the wrong section.
km34, I do view them both as equal and I treat them both as equals. It's they, themselves that have decided the primary/secondary situation. On the surface it appears that way too as I live with one but due to other issues related to my accident I stay with the other one night a week with a rare occurance of two nights a week. When we lived together for several months FWIW at the instance of the partner I live with we all slept in the same bed. Now THAT was a strange period of time for me.