I’m 16 years old. I was watching porn on my phone. My 13 year old sister walked in and I hid my phone and pretended to be asleep. She called my name, but i wouldn’t open my eyes. She proceeded to take off my blanket, pull down my gym shorts and underwear, and sit on my cock. It was at this point a “woke up” and grabbed her hips and slammed her ass down on my cock. She gasped, saw me, smiled, and continued to ride my cock. After i painted her asshole with my cum, she revealed shed been doing this to my father for three years, and to me for the past month. The next night, while my mom was out grocery shopping, i walked into my dads room, holding my sisters legs while my cock was in her ass. When he saw us, i slammed my sister down on his bed. My father immediately pulled down his pants, stuck his giant cock in her pussy and we fucked her for almost a full 2 hours. Afterwards, my dad shoved his cock in my ass as my sister sucked my dick. I was in so much pain, but it also felt so good. I let him cum in my ass, and that sent me over the edge, filling my sisters throat with sperm. For 3 years, we did this nightly, until i moved for college, but my sister occasionally comes over to let me fuck her.