AITA for refusing to share my pizza with my adult stepdaughter and her boyfriend?

My dad got married to another dad a couple of years ago. His husband has one daughter from a previous marriage who is obviously a step-sister to me. She's my age and has a boyfriend. I don't really have anything against either of them, they're just not my cup of tea. They're also spoiled as fuck and the husband is very much a moneybag, no job and his father pays for everything, including his daughter's expenses. <br><br>Over the holidays, my family and my dad's husband's family decided to have a gettogether at our house. I'm not much of a cook, so I decided to order a couple of pizzas and have a few drinks. I live in a separate house from my dad's one. I'm not a poor student, I have a part time job and I'm comfortable with money, so I can splurge once in a while. I was in the kitchen when my step-sister and her boyfriend were looking at the pizzas and complaining about how I only ordered two when there were obviously people that were hungry. I have a big problem sharing my food, just like my dad. We consider it very rude and impolite to ask people to share their food, let alone take it without permission. I told them that the pizzas were mine and if they wanted some, they could order theirs, I wasn't making enough money to feed a whole family. They told me that I was being selfish and that I was also eating their food, which was a lie since I didn't eat anything that they brought. I think they mistook me for one of their friends that they can boss around because theaudacity they had to tell me that I was being rude by not giving them some of my pizza. They started raising their voices and calling me an asshole and other names, and I really don't tolerate that kind of behaviour from anyone. I told them to fuck off and that if I was an asshole for not sharing then they could go fuck themselves and kicked them out of my house. <br><br>Now they're calling me an asshole and a terrible person to my dad and his husband. My dad knows me and how I am with my food, so he didn't take it too seriously, but his husband is another story. He said that I was being rude for not allowing them to eat when they were hungry. They were not even poor or anything, but he said that I was being selfish and I should have let them eat or ordered more for everyone. I think that's bullshit. AITA for not wanting to share my pizza and for kicking them out for calling me an asshole?