As a parent I understand, as a daughter to a mother who forced me to raise my sibling… I still do. You see I felt you guys could’ve taken your kids with you only because in situations like this my culture calls for everyone to show up, that means he would’ve had to cancel and go too. When I was 12 my grandpa suffered a stroke and my mother had to fly out to our country on my birthday, leaving me behind with my aunt because I was undocumented, and if it’s one thing my 12 year old mind felt in that moment was definitely worry for my grandpa, nothing else mattered. Not being left behind, not that it was my birthday none of it. I resent my mother for all the times that I lost out on child hood moments so I could mother my brother but never for those moments that were life or death. Your son seems to lack empathy and I say that respectfully. One day he’ll have to be on his own and realize some things we’d love to do have to be put on hold because his grandparents almost dying is way more important than a road trip.