I'm sorry that you had to go through that as a kid it has to be hard to be put into a position like that, I would think that the loyalty that you have with both parents would have to be strained. It's not a situation that a parent should put their child through.
So was me not being aware of my mother's drinking denial or was this simply not being aware?
I think that it was because you were an adolescent you were being asked to do things that most of your peers didn't have to do, they probably had different problems at home or a small fraction if any had to monitor the other parents habits.
It sounds like your mom was passive aggressive instead of facing your dad she was going around it with you, she should have thought about your needs and how her actions affect you. To a degree you were seen as object to fulfill her desire with your dad.
Maybe she was in denial, I've always thought that people that struggle with substance abuse are struggling with pain or trying to cope with the pain by using something to numb it, maybe they're not aware of the core reason why they drink. Like attracts like, your parents were probably both struggling with their own issues that they didn't know how to cope with, your mom was probably really stressed with chaperoning maybe she didn't know how to act around your peers or the people that were in charge of your party, maybe she felt a lot of shame and didn't feel worthy and coped with it by drinking.
I'm not making excuses for her behavior with how she treated you all I'm saying is that it's invalidating when someone just sums up someone's addiction by saying that they're a druggie or a drunk it's labeling something without peeling back the layers and looking at the reason why someone behaves the way that they do.
What was your mom's childhood like if you don't mind that I ask?