How would you feel if?!

[Nosugarcoating]

So basically....
Close friends with this woman for 5+years, known her longer but our life situations brought us closer. We went through similar things & supported each other. (Call her friend A)
Recently I have become close to another friend (Call her friend B)
Who I have also known for years.
So FA basically doesn’t like FB.
FA has made it clear she doesn’t like her & that I should watch my back etc.... so I continue my friendship with FB & FA de-friends me on social media, our friendship becomes more distant & no I just feel it’s all awkward. I would never expect FA to socialise with FB.
So recently when I was with FB & FA was with other friends. I over heard her mocking me.
I feel hurt as I have been nothing other than what I feel is a good friend.
Am I wrong to think you can be friends with other groups of friends & choose your own friends. Also to take ppl as they are. Not on something that happened 15+ years ago. We all change & grow in to better humans with life experiences.
What would you do?

I'd carry on seeing the people I liked and not the ones who were being mean about me.

Yeah you can have different groups of friends i do , FA seems to want u to herself and doesnt want u to have any other friends.be friends with who u want to be, FB id stick with her & FA id keep the distance its her loss u can be friends with who u want to be not who she says, ive had to do this with one of my friends it was hard & hurt but i had to do it x

F A is a Fud and you're way better off with her out of your life...