Little bit of a back story. My sister moved away for a while and whilst my children were young me and my mum would do a lot together and were close. When ds moved back home, wherever we went mum would invite her and her husband. It didn’t matter if it was a trip out for coffee or a school event. After a while I became worn down with this and told mum if I was giving her an invite it was not for her to extend it. She disagreed and said we were family and this was how things are. With this I stopped inviting my parents places and do not see my sister much as we don’t have much in common.
On to today. It is my son’s 21st birthday soon and I asked if my parents wanted to go for a meal. I would be covering the cost of this. She then said she would have to check if my sister and family are free. I pointed out it was just an invite for my parents. She took offence to this and kept saying we’re all one family. I now feel guilty that i am excluding them however my son is not close to his auntie and does not see her often. The meal was his idea and he asked for the grandparents to come but did not mention asking my sister. Am I unreasonable for not wanting to invite them?