Me and my step brother

So he thinks am supposed to apologize

I got home after school and heard a girl moaning and it was coming from Tonio room. I walk up the stairs I open his door to see my friend Katia Martín we were friends for the longest we went through everything together and I knew since my mom married she was using me to get to Tonio  but this was worse she is have sex with MY STEP BROTHER!!! I was so much in hurt, rage, sad, and hate. When Katia saw me she looked up and got off my step brother in a dash and says "Verónica its not what you think I promise". I just looked at her looking dead inside and then I turned around and go to my room I closed my door and locked it and slid down to the ground. I didn't go to school and then I got text from (guess who) yep your right from Katia. I told her i hated her and I never want to see her again and if I do she will regret it I texted that to her not reading her text. After that text Tonio un-locked the door and pushed the door open and said " Verónica apologize to Katia about what you texted her". I told him "go fuck off get out my life all you do is mess till you get your way so leave" he did not leave he stayed and waited for me to say or do something I don't move im hurt Katia knew I had a crush on Tonio and yes I know he's my brother but hes my step brother total difference. I hated her with a passion.