Last month my Mum celebrated a big birthday. Earlier in the year I asked my siblings if they were free to take her out for lunch, knowing we'd go out in the evening but thinking it would be nice to spend quality time together. No one replied to my message. Fast forward to her birthday. I turn up at the restaurant and after we had ordered my brother pipes up that the menu has the same niche dish as the pub he had been to at lunchtime. A small number of questions led me to find out all 4 of my siblings had been for lunch with our mum and I hadn't been invited. I was gobsmacked and understandably didn't want to cause a scene. My mum noticed I was quite quiet and asked what was up. I couldn't help showing my upset. She didn't apologise per se but said she thought I'd be busy at work. No particular reason why I'd be busier than my siblings. I'm supposed to be seeing her on Monday for our annual Christmas shopping trip and I'm not sure I want to spend time with her. I'm really really upset. What can I do?