Yes, your kids are your priority but it if was your W's night she should have planned better. She knows though she doesnt have to plan better because you will always drop everything and run to her aide when it comes to her not arranging for ample childcare when she has made other plans (sister to airport).
I would have said... "Gee, W, sorry I cant help you out on your night with the kids but I have a date and I cant be late!". She doesnt need to know your "date" is AA and if you said it cheerfully it would not only surprise her that you didnt come running to help her but again, you missed the chance to create mystery. And you totally skipped out on something you *need* and made it secondary when it should have been a priority.
What CityGirl said. ^ This should have been your first priority.
