AITA for making my parents pay for a bus ticket home after what I saw at the dinner table?

I am 14. My dad is a single parent and has three kids. Me, and my two brothers. My dad had a girlfriend when I was 11 and she didn’t want to have kids. I convinced my dad to let her adopt me, but she refused. But then I started to feel something for her and I told my dad I liked her. Then I started to like her more and more and I was happy to be her surrogate daughter. Then she got pregnant. She convinced me to let her abort the baby and I refused. She gave birth to my brother and I was happy to be his big sister. My mom is overseas visiting her family and couldn’t be there. My. Dad’s. Girlfriend. And I helped my mom. Named him. I’m so proud of him. <br><br>But tonight we were sitting around the table eating dinner. My brothers dad has a daughter and she came over. She’s 14. She kept calling me her brother’s sister wife. I ignored her. She’s weird. She tried to cut my brother’s meat for him and I told her not to. She tried to push me away. I kept telling her to stop and to leave us alone. She said it was rude that a girl was raising her brother and girlfriend’s son and she would teach me how to be a good woman. I told her to shut the fuck up. My mom was screening my calls. My dad was laughing and my brothers girlfriend was laughing. But the girl was upset and tried to call me a slut and my dad stopped her. He told her if she couldn’t behave herself she could go home. She went home. <br><br>My dad laughed until he coked out from laughing. Then he told me to go to my room. I said I wasn’t going. He told me to shut the fuck up or he’d make me. So I shut the fuck up and went to my room. Now I’m here sitting on my bed waiting for my mom to call me. I’m so angry I could spit. I’m so fucking mad. <br><br>My dad came up to my room. He said I had to go home. I said no. He said he’d throw me out. I said fine. So he threw me out and I rode my skateboard home. When I got home I slammed the door and took the phone from the wall. My mom called and I didn’t answer. <br><br>Now I’m thinking about what I saw and I’m so fucking mad. I’m going to tell my mom everything. And I’m going to tell my brothers girlfriend everything. And that girl everything. And my dad is such an asshole. AITA?