This all seems really sensible.
I guess what I'm wanting is to be part of a household - knowing my partner and I are really committed to each other, regardless of who else adds to our gestalt. I would not mind being part of a household. I want the "marriage/house/comfort/long term" kind of life that everyone else seemingly gets to have. I'm open to considering being "someone's other spouse" as long as I get to be a spouse at some point in my life!
There may be some inherent imbalance here because I'm lesbian, though, not bi.