Some girl in our senior class is planning a cookout at a lake for senior skip day in a couple of weeks. She’s rented pavilions , will provide some of the food (you have to bring something if you want to attend) and is doing most of the planning for it along with her friends. This is not a school sanctioned activity it is something that she is personally doing 

She’s invited a majority of the senior class (our class is pretty small with only 102 seniors) with the exception of some kids. Most of these kids not invited are kids she considers unpopular or just doesn’t like. One boy came up to me and said he and his friends would like to attend and asked for the location of the cookout. He told me that he, along with a lot of other kids didn’t get invitations to attend. I told him he’d have to ask her if they could go but he asked me if I could ask on their behalf since I know her better. 

They kept on asking me for the location and time and I kept telling them to ask her. They kept bothering me until I told them that she didn’t like them and didn’t want them there or else they would’ve been invited. I told them I didn’t feel like making a case for them because she’d just get mad and tell me that since she planned it she decides who goes and who doesn’t. I feel like she has a point it’s not right for me to force her to invite people she doesn’t want. I wanted to avoid an argument I knew I was going to lose so I just let them get excluded AITA?