This morning my dc's were at a holiday club which was to end at 12 noon after which we were going to the park with friends (this was reconfirmed when we dropped off our children and picnic food bought). At 11 am I decided to call my mum to have a quick chat. She announces my brother and his two children are coming to her house and were due to arrive any minute. They live about 45 mins away from her. She asked me if I was coming over and I explained I hadn't planned to as (a) children in club and (b) short notice would mean altering plans. She seemed annoyed and kept saying "so you're not coming over, I thought you'd want to see them". I ended up telling her I shouldn't be expected to change my plans with short notice and had db wanted to see us he should have called earlier or got her to. She told me to "grow up" . Should I have cancelled? Our picnic was little wet but we made the best of it .