I have a group of friends, 3 women. We meet up a lot, talk most days etc etc.
I have another friend who is not part of the above "group" not because of any falling out, just doesn't move in the same crowds, she has her own friendship circle. We don't hang out with the same people but we are good friends and have been for a long time. I'll call this friend A.
One of the 3 women in my friendship circle has met another woman ill call her B. She has started being invited a lot to outings with the group and is becoming more and more involved with everything we do together as time goes on.
The problem is that A & B do not like each other whatsoever. There have been some things gone on in the past between them which I won't go into now and they just don't have a good relationship at all.
I'd never spoken to B before she started coming out more with us after becoming friends with one of the other women and whilst I'm not rude or anything obviously and am friendly to her when we're together, I'm not close to her either. The problem is A is now upset that I am "hanging out" with B and is being off with me about it despite me saying we aren't best of friends, she just knows one of my other friends and so invited by them sometimes.
I feel very awkward now and like I'm stuck between a rock and a hard place. B has never done anything to me personally and I still don't know her that well, it's never me that invites her out but I'm also not going to be rude or standoffish with her when my other friend is close to her. But then I also feel bad for A that I'm now seemingly hanging around with and being chummy with someone who she has had big issues with in the past.
(Fwiw B does know that I am good friends with A).
What do I do?!?!?