My inlaws are lovely generous people, but illness has resulted in them living in an untidy and unclean home. When visiting I have cleaned a room to help out, encouraged their other children who live locally to help more with the cleaning and purchased and fitted a toilet seat. The first time I visited I left the next morning. Since then I've tried to accept it, but it's not a small issue. The floor is rotting in the bathroom, rotting food on the stairs, utterly filthy toilet, stuff everywhere on every surface. I saw a piano used once for icing a cake, the rack was placed on the keys as there was no other available surface. When I purchased a toilet seat one visit, there hadn't been one for years and they were very offended.
By far my biggest issue is the kitchen, in which the cooker is never cleaned and is encrusted, the floor is similarly so, and there is washing up piled on every surface. Food is often left out. When I visited once, there was no bin. There is frequently cat litter all over the floor, although shredded paper is often used in the litter tray. The fridge is never emptied and is refilled, leading to rotted food dripping onto food below and the sink is often inaccessible.
Each Christmas we have visited for a week, we don't live close enough to visit for a day. This year we have a newborn and I'm concerned about taking him into such an environment. I had asked to stay at home this year and have them visit. Question is, AIBU to refuse to go? Knowing it will upset my MIL to miss Christmas with the new baby.