DH has a 10 year old child with his ex wife, lovely kid. We have him every weekend, I get on great with him. Have had some issues with his mum and her new husband over the years but seems to be settling down now. He was bought an experience day for Christmas from his maternal grandparents but with covid this hasn't been able to happen as yet but is now booked for next Sunday. We are dropping him at the venue after DH contact time, grandparents have said we can stay and watch. DH is keen that's fair enough and it's nice that he wants too! He suggested we both go, I said why on earth would I want to spend most of the day with the ex in laws on my only day off that week especially after the trouble his ex has caused over the years. I have clearly upset him and feel bad but AIBU? I have made it clear if he wants to go then that's lovely (I may even get the house to myself for the afternoon, once in a blue moon luxury!)