AITA for buying snacks that my sisters with braces can’t eat

I (f13) have two sisters (19f&17f) they both got braces they used to always eat my food so I’ve decided that since they have braces they can’t eat hard things so I’ve been buying the best tasting chips that are hard and crunchy they can’t eat I’ve also been buying skittles and soft candy yesterday my sister (17f) wanted a snack and tried to take mine I wasn’t home so she just grabbed them when I got home my sister (17f) started yelling at me on why I didn’t buy any snack that she could eat I got mad at her and told her to buy them herself and I stormed off I stayed in my room my mom got home she also yelled at me and called me an asshole so am I?