DP brother has booked a weekend away for them to celebrate his birthday. Nobody asked me about dates and it's the same weekend I'd already planned (and checked with DP) a day out for my friends birthday. Getting childcare is really difficult as we live away from family and I feel annoyed that everyone just assumes I'll sort all this out/ change my plans. AIBU that someone should've checked with me first? I feel annoyed that there is an assumption DP doesn't have any real responsibilities and that the buck stops with me?