My take is that they may be bisexual, but they may not be biromantic. In the sense that they're down to fuck women, but prefer dating men. It's a differentiation you usually only see in the aro/ace/agender community (separating romantic vs sexual attraction), but I've started to wonder how many people have a romantic orientation that doesn't fully match their sexual orientation.
Lesbians
A community for lesbians, people whose loved ones are lesbians, people who want information about lesbians, queer people, and allies!
-
Trans lesbians are lesbians and are welcome.
-
Lesbians of other nationalities, even ones you “don’t like”, are welcome. Feel free to speak another language if you can, as long as you tag it with the right language flair.
Fwiw, I've had two bi partners break up with me for women.
And I ain't mad about it. For me, if it's something that fundamental, as in them needing what being with a fellow woman provides, I know I can't provide that. I'm cis-het and male, so there's a wide range of experiences I have no access to, there's the physical differences, so getting broken up with on that basis isn't something that's on me. I didn't fuck up, it wasn't something I could have met their needs for and didn't. So, while it hurts, it somehow hurts less than a breakup for other reasons.
It's not the same thing as your situation, I know. I'm just hoping that maybe it can give you a different way of looking at your situation and maybe take some of the sting away, turn it down a notch.
Fwiw, I've also tried dating people that were poly, or in an open relationship (they aren't the same thing, but they can feel the same when you're a third wheel). It ain't for me either. Like you, what I really want is committed monogamy. It works for me. Which makes me agree that it's probably time for you to make that a hard no in your life. It isn't for everyone, and trying to make it work sucks for everyone involved when it won't.
honestly you should never date somebody who prefers the company of others over you, not to say that they cant enjoy the company of others, rather that they should not prioritize those other relationships over the one they choose to be their partner.
im terribly sorry that you dont have this experience, and i often felt this way when i was dating men too. dating women hasnt been exactly the opposite or anything, and maybe its just because im more picky about my partners now, but dating women has shown me that i really do deserve somebody who will care about me and prioritize my needs, and tell me that they love me and care about me and actually mean it when they say it.