Trans Man Partner
This point has been brought up to me multiple times as a hypothetical: "What if a lesbian's partner comes out as a trans man, but they're still attracted to their partner?"
This point comes across as rather transphobic, in my opinion. It is totally valid to still be attracted to your partner after their transition, but if that is the case, then you are not a lesbian. Still identifying as such , even if you add "bi" to the beginning, doesn't fully acknowledge your partner's transition, and it comes across as misgendering.
Just call yourself bi with a strong preference, or omni, or even a sapphic, as it emphasizes your love for women while not erasing your partner's gender.
Choosing to Use the Outdated Definition
I'm sorry, but words simply just don't work like that. Modern conflicts create modern solutions. The conflict happened 30 years ago, and the solutions have been 30 years in the making. You can't just undo 30 years worth of linguistic evolution just because you want to. I get that as an older sapphic, it may be frustrating and confusing to see the words you've used for ages be redefined and altered, but you can't control that, we can't control that, and all we can do is change and evolve with the community and our language.
Glossary
Sapphic - an umbrella term that covers any woman or nonbinary person attracted to other women or nonbinary people, regardless of other attraction
Lesbian - a woman or nonbinary person only attracted to other women and nonbinary people
Mspec - multisexual spectrum; a spectrum of attraction to multiple genders
Aspec - a spectrum of lack of attraction, covering any identities that are not allosexual and alloromantic
Allosexual/Alloromantic - orientations for people who experience "normal" levels of romantic/sexual attraction
Bisexual - sexual attraction to one's own gender and other genders; a fluid identity that covers most mspec experiences
Pansexual - sexual attraction to all genders with no preference
Polysexual - sexual attraction to many, but not all genders
Omnisexual - sexual attraction to all genders, but with preference
Nonbinary - an umbrella term for all genders that aren't binary
Works Cited
The Bisexual Manifesto
The Am I A Lesbian? Hyperdoc
Oxford Dictionary Definitions
Another Kind of "Chilly Climate"
Vanderbilt.edu Resources and Definitions