AIBU to ask my BiL to look after their 2 kids for a couple of hours (actually I guess probably 4 hours total with travel time) while my sister comes with me to choose my wedding dress? He refuses to do it, and has called me a spoiled brat etc for asking. His POV is that he is a SAHD during the week and needs a break- to be fair, it is a demanding job- one of the kids is mildly autistic/ aspergers (although at school during the day) and the other is a toddler (mornings in nursery). I truly understand that it is hard on him, but it was a 4 day weekend so he would have had a break the rest of the time and it is a once in a lifetime special occasion (important to me more emotionally than practically to be fair.) i have never asked him to do anything like this before, and he has never let my sister go out anywhere without him on the weekends since they had kids 5 years ago, as he says the weekends are his only chance to have a break and my sis should be on duty with the kids. She won't be coming to my hen night etc for this reason. they won't use babysitters and there's no one else that can really help out.