Mother and Brother do not get along

My brother has alot of grievances against my mother over our childhood. He prefers not to be around her. He has made this clear but my Mom just cannot accept it. Even when he is flat out rude to her, she always comes back around begging for time with him that he doesn’t want to give. She vacillates between sorrow and anger over this and spends many hours sharing those feelings with me, which upsets me in return.

She tries over and over again to plan family get togethers with all of us. I do not enjoy these at all. These events are excruciating for me because they are so annoyed by each other and tense around each other. Sometimes they fight and my Mom will cry or my brother will walk out. Other times, she will get mad and tell him off.

Even if it goes well, which is rare, my stress level is through the roof. From my perspective, they are actually quite similar in personality and I think that is why they butt heads. What I have come to realize is that I do not want to be around them when they are together. I keep doing it for her sake but it is stressful and exhausting for me.

All my life I have been the mediator between them – always trying to help them be happy when around each other and usually failing. I don’t want to do it anymore.

How can I set a boundary and tell her that I will not accept any more invitations to be around them together anymore and not to ask me anymore? I know it will break her heart – she will be cry and then very angry at me for awhile but after 41 years of this, I just want to choose not to put myself in that situation ever again. I love spending time with her one on one. Why can’t that be enough?