I dated my sister

So, my only sibling is my twin sister. We were raised together, even though after our father passed away, my mother started dating a man with a daughter of his own at the age of 15, around the same time my sister and I turned 16. After that, my sister abused my step sister, continually. She slapped, punched, kicked her in the balls, even forced her brother's head down there to suck and then, she even forced her brother's cock in my step sister's ass. She tried to get her brother to claim he was my step sister's father. My mother is disabled and while my step sister was a bit of a wild child, she was not that wild. Knowing all of this, my sister was still allowed to participate in my step sister's lives and she even dated her brother, after she got pregnant by another man. While my step sister worked a full time job as a firefighter, my sister would sleep in late, drink, use drugs, and reduce she brother to a skid mark, at least twice. She even forced him to fuck her in the ass with his two fingers. The first time, he tried to run over her and her kids. My step sister, who resented my sister because she treated my mother like a piece of shit, started using my sister's own racism against her by dating a black man. Now, my sister is more racist than any person I have ever met. She resented having a black step sister and brother and my mother having a black boyfriend. She dated a man who was racist and only liked women with big butts. He would get mad if she ate too much, meaning she starved herself to 90 pounds. My sister is around 5'10". After he found out my step sister was dating a black man, he tried to get my sister to sleep with a black man. She shamed my sister for not being able to even get wet when she was fingering her. It all came to blows when my step sister started working out and eating healthy. She was losing weight and my step sister was able to get my step sister's boyfriend to get her a job where she was able to lose a lot of weight and then, I started hanging out with my step sister. My sister never made time for me and because of her, I had a fear of women and was terrified of dating girls. I was in college and taking speech communications, but I never showed up. My step sister found out and made me go to my classes and started taking them with me. We started dating, worked out together, developed a body count together, and then she got pregnant by my step brother. So, I dated my step sister from the time we were around 15 until we were around 28, which is when I started dating my sister. We had a 13 year age gap between us and I was around 25 when my step sister turned 18. We only dated for around 9 months and that had a lot to do with my step brother's sister threatening to turn me in to the police for allegedly raping her. After that, I started dating my step sister's brother's sister, but she did not know about our family connection, only that we had the same last name. We are still together and I still live with my step sister and her son. She never liked my sister and she never made me feel bad about dating her, so now I dated my step sister and my real sister. I still love her.