My friend has a crush on me

She didn't tell me, her sibling did. I don't like her like that though. She's like a little sister to me. But part of me is angry bcs this is my first chance to actually date a girl, but I'm currently in a ... thing? with a boy(I'm bi). We're dating, but not, it's really complicated. Which is why I have a pretty pessimistic outlook on love right now as well. I'm not physically attracted to her. Emotionally, not really, either. But sometimes I thought of what it would be like to date her. And I feel like if I spend my life dating only men, then I can't call myself bi. And I know that's a toxic way of thinking but it's so frustrating to not feel valid. And I'm not breaking things off with this boy for a girl I don't like. I just feel really invalidated and confused. I feel like I should like her back but I don't and its so dumb. I like women, I have/had crushes on so many, but everyone keeps telling me I'm straight, either because they don't realize being interested in a boy doesn't eliminate my love for women, or they don't know I'm queer and think if they say "you're straight" enough I won't "turn gay."