When I was in my early 20s I briefly dated a girl who told me she was having feelings for another woman and was being curious, she eventually broke up with me in order to be with her, but we remained good friends after that.
Eventually she came out as a lesbian and when I told her that I was bi she immediately ended our friendship all even yelled some slurs at me.
I have a similar story to share.
When I was in my early 20s I briefly dated a girl who told me she was having feelings for another woman and was being curious, she eventually broke up with me in order to be with her, but we remained good friends after that.
Eventually she came out as a lesbian and when I told her that I was bi she immediately ended our friendship all even yelled some slurs at me.
AFAIK she's married with a guy and has kids now