My parents broke up when I (16m) was really young. I lived mostly with my mom until I was 10. My dad was really inconsistent and hardly played a role in my life. My mom was another trainwreck who tried to put me first but her addiction got too bad and I had to be taken from her custody. My dad took me in and even though I lived with him I didn't see him much or benefit from having him around me. He'd pawn me off on his brother or his parents a lot. Whenever I asked for anything he'd act like I was a whole grownup with money to spend on myself. His parents bailed me out a lot. They didn't even know I existed until I went to live with dad. He'd never talked about me and didn't even mention mom to them when they were together.

When I was 12 my dad moved in this woman and her two kids and they got married 8 months after, I think. Right after we moved in I found out she was married and her ex got arrested for trying to break into our house and threatening to kill my dad. So I found out thanks to that neat incident that he cheated. Because of the affair and stuff a DNA was requested to see if the ex or my dad were the father or her kids. Her ex is. But he doesn't see them anymore.

My dad treats them like his own and he's a real dad to them. He spends time with them, teaches them stuff, he pays for what they need and what they want. He spoils them in all the ways that he can. For a while I thought maybe he'd be a better dad to me too. But he still makes no time for me and when I ask for anything he tells me to buy it myself. Stuff I need for school or whatever fall in that category too. His parents will pick up the slack but it sucks.

It's made me bitter and it's made me avoid his wife and her kids. His wife doesn't pay attention to that. She probably doesn't care as long as dad takes care of her kids. But now that her kids are doing more stuff they want to hang out with me and they follow me around when I fail at avoiding even seeing them. I lock them out of my room most of the time so they're not in my face and any time they ask me to do something with them I say no.

My dad got annoyed by that the other day. I got home from work and sat down to watch a movie because nobody was home. But a few minutes into the movie he got back with the kids and they came running in to watch the movie with me. I went up to my room as soon as it happened and a few minutes after he ran up the stairs after me and with all this fucking attitude asked me why I ran upstairs when his stepkids came in. I told him I had sat down there because nobody was home and I left because they were in my space. He said they wanted to spend time with me and I told him I didn't want to spend time with them. Then I asked him where all this dad energy was when it was me. I pointed out how he couldn't give a fuck about me and left me with an addict and didn't even tell his family about me. But then he gets all up in my face because I won't spend time with his wife's kids. I pointed out all the stuff he does for them and how his brother and parents who only met me 6 years ago have done more for me than him.

He told me that had nothing to do with his stepkids and that the little girl and little boy downstairs looked up to me and loved me and just wanted their brother's time. I told him if he wanted me to be their brother he should have been a better dad. I told him just because he loved them didn't mean they should get everything they wanted. I told him I'm not spending time with them. I don't want them. I don't care about them. And he can work on figuring out how to make them less sad about it but I owe none of them anything.

He argued back and the kids heard us say a lot of stuff. Including what I said about them. Dad got so guilty looking and went to apologize but I didn't. Then he called me names for not caring about them and fighting like that with him in the first place. I spent the last couple of nights at his parents house because of it. His wife wants me to apologize to her kids and he told me as much when he dropped some of my stuff off at his parents house. I told him it won't happen and he called me a shithead. His parents told me it'd be okay and it'd get better. I don't know what they meant by that but they're good to me so I'm relieved to be here.

AITA for that fight and what I said?