Well of course I show up to interject... its expected by now. Most bisexuals have one partner at a time. They are attracted to both sexes, but that doesn't mean they form trios. They are monogamous with the partner they fall in love with. Could be a woman, could be a man. If you are thinking of someone with more than one partner (one of each) you are either thinking polygamy or polymory. Totally different ball-game. (oops, no pun intended)...
anyway, lots of gay folk have issues with bi-sexuals too, for some reason. Lots of people think they just can't make up their minds or that they don't have the cajones to take the flak that comes with being out as a gay person. Took me a long time to figure it out and be comfortable with it myself. But I now have friends that are bisexual, we talk about this, and I have come to understand them better. I guess you fall in love with who you fall in love with.
Now back to topic... not only is it cumbersome and time consuming to try to avail yourself of the over 1,000 protections offered heterosexual unions, you have the problem of the enormous expense to arrive at close (you can't get there 100%) to the same protections.
And going back to Brown vs the Board of Education - the ruling was: Separate but equal does not mean equal. Same holds true for us. If you'd like to see how this affects people, check out: http://www.tencouples.org/ the second couple have been together for over 50 years.
Sherry