I present to you... The plot of every movie about lesbians written and probably performed by straight people....
So there are these two women, both of whom are conventionally attractive femme-presenting but... one of them is slightly nonconformist in that she campaigns for women's rights! And wears pants! Because, you see, these women, live in the past! This movie is a period piece set probably in the early to mid 20th Century some time.
One of the women, a sweet, quirky young lady who always does as society expects from her, is in a boring relationship with a pleasant, but kind of bland male partner. He seems nice enough and yet... she feels like something is missing in her life. Then she meets... The other woman. The other woman is super flaming hot and intimidating, but in a femme way that straight people like, and she probably smokes, and she asks difficult questions like "Why can't women be CEOs in this period setting?" and "What if God is a woman?" and "How can you know love if you've never kissed another woman?" WOW. DEEP.
Little baby protagonist accepts to hang out with the other woman, and wants nothing more than to be around her, while all her friends are like "HAHAHA, it is almost as though you are in love with her! But that would be ridiculous in this period setting!" and protagonist is like "What, but... it is impossible! How can I, a woman, be in love with another woman!?"
She asks the other woman and there's like... immediately a steamy but very arty sex scene where they are totally naked on top of the sheets and you don't really see any details so you would be forgiven for thinking lesbian sex consists entirely of vaguely rubbing against each other or caressing each other's lips while taking turns to arch your back or neck while sighing.
Their love affair continues and gets serious and people start talking about how this is unacceptable in this period setting! Even bland and nice seeming male partner flips and says "This will condemn you to hell!" and protag realises he is right! Oh how sad! The two must go their separate ways. Protag stays with her boring male partner and is sad, and the other woman goes away to live her sinful sexy lifestyle with other women she can never love as much as protag and writes letters to her. IF ONLY they didn't live in this period setting where gay people are oppressed! IF ONLY they were friends with YOU, straight but totally progressive person in the audience! YES, NOW CRY! CRY YOUR EYES OUT OVER HOW SAD IT IS AND GIVE US ALL THE OSCARS!