AITA for buying the ready ones?

I 23F am a full time student and work full time. I live with my brother (26M) and his pregnant wife (25f) and their two year old daughter. The arrangement is I pay 1/3rd of the house and help with chores 1/3rd of the time. <br><br>They have a 3 bedroom house. I have one room, they other bedroom is the nursery and they have the master bedroom. <br><br>Ever since their daughter was born I have always helped with the chores even when I wasn’t living there. I would do laundry, and errands and cook three meals a day everyday for free. <br><br>In October I moved in with them and started paying 1/3rd of the bills. And also continued to do all the chores. They said they couldn’t afford to hire someone so I should do it. I was cool with it. <br><br>But when my wife got pregnant (edit: brother, not me), I felt it was too much so I cut back on all the chores. I stopped laundry and errands and cut down the meals to one meal a day. <br><br>The reason why I don’t do everything is because I’m a full time student and I work full time and I’m already living there rent free. <br><br>They got very upset and said I need to do my share of the house work. <br><br>So yesterday my brother and his wife were out and about and I was at home with their daughter doing homework. I wanted to eat and didn’t want to make a whole meal so I went and bought a rotisserie chicken. I brought it home and gave some to their daughter (she loved it by the way) and ate some myself. <br><br>They came home and were super angry that I shared the food with their daughter. <br><br>I don’t understand what I did wrong but I just don’t get it. My brother called me an asshole for buying a whole chicken and sharing it with his daughter. <br><br>Edit: My brother and family are doing ok financially. <br><br>Edit 2: wow thank you for the Gold and silver. I appreciate the kindness. <br><br>Edit 3: wow! Thank you for the Platinum. You didn’t have to do that. But I’m very thankful and it’s very sweet of you.