OK All,
Seems you were right to advise me to not let the kids go to my Mum's. They had a wonderful time! But were put in a really confusing and awkward position. My mum agreed not to allow my sister to visit whilst the children were there. It was my only stipulation. I made it clear that the children would not be coming if she was there. The children have been told why we do not see my sister and BIL and for them to see them at my parents could be worrying at the least for them as they know it would be something I would not like.
I text my mum telling her I wanted no more contact from her from this point onwards. Me or the children. As she chose not only to go behind my back, but to put the children in such a position.
I'm not at all surprised but sad now.
Because my father and older brother live with mum, I lose them too. Whenever Dad dropped off the children, you could tell he felt torn and caught in the middle. But ultimately it would always be her he would stand by, so I suppose he made his choice.
New year , new taking