My parents are divorced. They haven't spoken in 10 years. Usually my brother and I spend boxing day with our dad. This year, my mum has organised for my step-dads family to visit on boxing day (they usually come on the 27th) because she says spreading it over multiple days is too stressful. My mum wants my brother and I to be with her for when the family come, and she's also booked a meal at a restaurant for quite late the next day. I feel completely torn, my mum puts a lot of effort into christmas, but I don't want to duck out on my dad because I know it'll make him feel shit, and obviously I want to see him. What do I do? I'm finding it really hard to look at this reasonably and without getting emotional.
ETA: My dad goes to his sisters for Christmas day so its not an option to swap.