To want to stay friends with both?

[Minifootballteam]

I'm going to try and shorten as much as possible. I have 2 close friends. They were best friends for 10 years until 6 months ago, completely inseparable, never went a day without speaking etc.
Friend A is 15 years younger than friend B. Friend B has grown up children.
Friend B has a son-in-law the same age as friend A. There has always been an obvious spark between A and sil which has been an ongoing joke even with Bs daughter.
Long story short, A admitted to B that her and sil had kissed on a night out.
B and her family have made a HUGE issue, slating A all over our local town. Sil has been totally forgiven (I happen to know he has made several passes at A over the years which she has turned down)
A has been very quiet. Accepted she did wrong, lost her best friend etc.
My aibu is: B has said she can't be friends with me if I'm still friends with A. I don't want to lose either friend and, imo, if sil is forgiven surely A should be as well?

Following Hugh’s post, sweeping under the carpet and not throwing the bastard out isn’t quite the same thing as forgiving.

If she’s screaming at people in the street I’d suspect he’s (quite rightly) getting hell at home.

Everyone has forgiven him. If the story was told to anyone who didn't know both sides A would be the predatory whore who forced him into the situation.
Agree daughter has done nothing in regards to the cheating but she has also been disgusting in her treatment of her mother leaving A to pick up the pieces in the past.

You sound like you are sticking by A. So just do it and leave B to get on with things.

Also, sil has messaged A recently bragging about being able to talk his way out of anything ' and has also told my dh that he is getting no hassle at home or anywhere for his actions

I want to stick by both

Sil sounds like a dick but you are not friends with him so his behaviour is irralevant. I would attempt to stay friends with both but if B chooses to drop you that's her choice.

Don't offer opinions on this issue though it's nothing to do with you

But can you stand by both of them? Surely staying friends with A is going to affect your relationship with B unless you are discreet about it.

If I were you, I'd also block the SIL and cut contact with him. What a load of school kid drama. Who needs that in their life? I'd be encouragingg A to not have any contact with him either and telling her if she continues to, I don't want anything to do with it.

You seem to be defending A a lot and slating Bs DC a lot too.
Just be friends with A and B will do what she wants.

A blocked sil months ago. He messaged from a different number. My feelings about Bs children were known before the incident and haven't changed.
A has asked me to choose B if forced as she is comfortable alone but B needs support.
Sil is friends with my dh but dh has told him he's a complete prick

Well yanbu to want to stay friends with both but I think that's going to be quite difficult to do at this stage. The thing is you seem to have lived this whole thing with them both, you know every twist and turn of everything that happened before and since.

It's a bit late now I know but you really should have taken a step back from the drama quite a few months ago, then it might have been easier to say "I'm able to be friends with you both without it effecting the other". The truth is you're so involved that one might find it hard to believe you're not discussing this when you're with the other so one way or another your relationship with one or both will possibly suffer.

I agree with Coco that you seem over involved in the minutiae of all this & it will be difficult to take a step back now.
It also seems to have brought to the fore your negative feelings about B.s. DC.
You either firmly tell A & B that you intend to remain friends with both of them but won't be discussing the matter any further with either of them or just continue the friendship with A, as reading your posts your sympathies seem to lie with her & B has probably picked up on this.