So your D11 has been away for what, a week now? And the gist of your post was how how your W looked. Your D11 got a mention at the end of your post.
Think about that. There are hot chicks all over the place but you seem to only notice one.
Is tonight your W's night w/the kids? If so then I think you should have told her you had plans that cant be changed and had her figure out the schedules with the kids and her sister and the airport. It seems odd to me that you are okay with her basically saying "ok, now I am done with you and you can go do what you planned to do" AND that you told her things has already been blown.
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. Sure, there is always another meeting somewhere but you had plans to go to that one and right now you need to stick to what you have planned barring an absolute emergency (this was not an emergency, it was poor planning on your W's part). And yes, IMO, it was a "thanks whipping boy" hug.