AITA for eating a potato when I watch Avatar

Okay so I live with my dad and step dad. Recently I started watching Avatar because I have nothing else to do. My stepdad bought a bag of potatoes and i started baking then eating them. Normal stuff right? Well yesterday I was watching Avatar and eating my potato when my dad comes in the living room with the bag in hand. He tells me not to eat them anymore. I was kinda confused because nether my stepdad or dad eats them so its not like i’m taking them from someone else. I asked him why and he proceeded to explain that its a waste of money because i’m the only one who eats them regularly and I only do it when i’m watching avatar. I tried to explain to him that i don’t only eat them when i’m watching this show and that I actually like them. But he basically said that his word is finally and that if i really like them then i should get my boyfriend to buy them for me which is weird be he almost always get upset when i ask my boyfriend for things instead of him. I told my friends about it and they think its funny that we got into an argument about potatoes and just told me drop it.