My name is Colton. This is a story I'm not sure I should tell anyone. It's partially because I know what happened is wrong and it's partially because I did not do anything about it. It started on a regular school day. My friend Steve had been talking about a video game he got for his computer. I was kinda the poor kid in school so I did not have a computer or games. He offered to show me so I walked home with him. When we arrived at his house he let me know that his parents would not be home for a few hours so it would just be us and his younger sister, Sarah. I knew about his sister from school. She was somewhat popular for being pretty and a little skinny. She had light almost blonde hair that always clung to her face in places. Her eyes were bright blue and they peeked out through her bangs like a wild animals. I hated to admit it but all of Steve's friends had a slight crush on her, even me. She was in the kitchen when we entered the house, standing over the stove cooking something. "It'll be done soon," she shouted upon hearing her brother enter the house. She came into the living room a moment later holding a ladle and wearing an apron. She jolted when she saw me. "Hi," she responded quickly. "This is Colton, he wants to check out that game Dad bought me," Steve informed her. "Hi Sarah." I waved to her shyly. "I wish I'd known earlier. I'd have made more food." She hurried back into the kitchen. I noticed then that she was not wearing her jeans from school anymore. She must have taken them off upon getting home. It was understandable. This was her house and jeans are always uncomfortable if worn too long but I was still staring at her panty-clad ass for far too long. "Like what you see?" Steve asked smugly. "Um, sorry," I tried to apologize. "Even I know she's a tight piece of ass," he was not offended. "I wonder if she'll put anything on now that she knows you're here." Rather than waiting to find out, we headed upstairs to his room. He sat down in a swiveling office chair in the corner in front of a desk with a computer set up on it. It was a nice computer, definitely better than most of our friends could afford, especially me. I sat down on the bed and waited as he booted up the new game. Just as he was getting to the loading screen, the door to his room opened. Sarah was holding a tray of food. There was definitely enough for two. "Oh, are you giving your portion to Colton?" Steve asked. She simply nodded. "No, you didn’t have to do that," I argued. "It's fine. We know you don’t have anything to eat at home," Steve made me feel extremely guilty. "What are you playing?" Sarah stared at the computer screen with interest. "Come and see." Steve patted his lap. I was surprised when she trotted over and sat down. She was no longer wearing the apron and was now just wearing a shirt and panties. I placed my hands over my lap to hide a growing boner. Sarah squeaked when she sat down. I quickly realized it was because Steve also had a boner that was now poking into the crotch of his sister's panties. She blushed feverishly while trying to look at the screen. She kept closing her eyes and trying not to moan as Steve intentionally rocked her in his lap. It took me a moment but I quickly realized this was all intentional. These two siblings were incestuous and they were getting off to me watching them. "Take them off," Steve whispered into Sarah's ear. She shook her head in protest but he slid his hand under her shirt and started to fondle one of her breasts. Reluctantly she hooked her thumbs in the hem of her white panties and slid them down to the floor. She kicked them off in my direction. They landed in a bunch at my feet. I was not sure what I was supposed to do with them. Sarah gasped as she felt her brother's bulge rubbing against her now bare exposed cunt. The hair between her legs was also blonde in color and was quite short. She must have only hit puberty recently. I found myself wishing I could touch her but only able to watch as Steve did just that. He used his knees to push her legs apart, exposing her glistening cunt to me. He then ran one hand down her stomach and over the hair of her crotch before touching her cunt lips and curving his fingers up into her. She looked at me with the most innocently embarrassed expression I have ever seen. Her cheeks were red and her eyes were twinkling as if she was about to cry. Slight drool dripped from her glistening pink lips as she opened them to moan. As Steve's fingers disappeared inside of her repeatedly, she rocked back and forth on his lap in pleasure. "I'm going to cum," she whispered almost inaudibly. Steve pressed his lips to hers and muffled the sound of her screaming as clear liquid shot out of her cunt around his fingers. After multiple convulsions, she broke away from the kiss and turned so our eyes met. "Don't look at me," she pleaded as she slumped against her brother. It was a pointless request though. The last thing I was going to do was stop. When Steve pulled his fingers out of her dripping cunt, it stayed slightly open. She panted with relief as he worked on undoing his own zipper. She gasped in surprise when Steve's cock sprung out of his pants and slapped against her sopping cunt. He guided it with his hand and bucked his hips upward, filling her wet cunt with himself. Tears spilled forth from her eyes as she shook her head at me, begging me not to watch her shame. Each thrust made her moan more. Steve pulled her shirt off over her head, leaving her completely naked on his lap. I realized at that moment that she had not removed her jeans for any other reason than preparation for this. Despite how shy and reluctant she appeared, she had been anticipating getting fucked by her brother and was probably disappointed when she saw me enter the house with him. It did not stop the rambunctious siblings though. Eventually Sarah began to push off of the chair's armrests, gaining more height and then dropping down on her brother's cock with more force. She was enjoying impaling herself. He looked less comfortable though. Each time she dropped, she screamed out, slightly annoying him. "Hey, Colton, come shut this slut up." He pushed his index fingers into her mouth and pried it open sideways. I was shocked by the way he referred to his own sister and even more so by the invitation. She was trying to shake her head but he held it still, forcing her to look straight at me. "Come on, stop hiding it and whip it out!" Steve ordered me. Sarah trembled when she saw my cock spring up from my pants. I swear it was bigger than normal just due to watching for so long. She looked at me with defiance as I approached her but Steve held her mouth open. The tip of my cock barely touched her lips or the walls of her mouth but I felt her hot breath as I pushed it all the way in. Finally Steve let go. She pulled back immediately but he placed one hand on the back of her head and shoved her forward again. This time the slimy feeling of her mouth enveloped me as she closed it in surprise. Her squeals were muffled. Every time Steve loosened his hold on her head she tried to pull away. Eventually I got slightly upset and simply grabbed the sides of her head and her hair and shoved her all the way down my shaft. Her throat opened up for me with a stabbing squelching sound and she promptly threw up all over my cock. When I pulled out she was sobbing. "What the fuck did you do that for? I've never given head. Steve only uses my pussy!" she wailed. "You're okay," Steve dismissed her concerns while thrusting up into her. Her eyes crossed as she rose off his lap. She looked like she might puke again from having her stomach churned from the inside. More than upset now she looked confused. Her tongue was hanging out and drool was sliding off of it invitingly. I grabbed her head again and slid my cock back into her mouth, all the way to her throat. She gagged but did not puke this time. "Ooh, she just tightened on me," Steve moaned in delight as she squeezed her legs together. I stepped back and leaned her downward so each thrust from him shoved her deeper onto me and vice versa. For a while we slid her back and forth between us like a spit roasted animal. She gurgled and squealed the whole time. We did not relent until Steve felt warm liquid running out of her crotch and down her legs. "Dude, she can't breathe. She's pissing herself." Finally I pulled out, leaving her gasping for air. When she caught her breath she resumed her defiant look. "Stupid fucker!" she shouted at me. I smiled down at her messy face. Mucus was dripping out of her nose and what little makeup she wore was streaked with tears. "You could have… ug… killed me," her complaint was interrupted by Steve thrusting into her again. I reached into her mouth with my fingers and pinched her tongue and pulled it out as far as it would go, forcing her to keep her mouth open. I placed the tip of my cock on her tongue and slid it back and forth, threatening to push it into her mouth again. "You really wouldn’t stop me, would you?" I asked. She did not answer, just grunted again as Steve thrust into her once more. Just looking at the messed up face of this girl as she tried to be defiant while still getting fucked by her own brother was enough to trigger my orgasm. The first shot went into her open mouth but she closed and swallowed right after. The rest splattered over her face, making her look even more used. I watched her gasp and hiccup with each thrust as her brother slowly brought himself to orgasm inside of her. He had his large hands around her tiny waist, holding her down so that not a drop escaped. He filled her cunt with his incestuous cum entirely. When he finished, she leaned forward enough to fall off of him to the floor. She lay there panting for several minutes, twitching every once in a while. Finally she propped herself up with her head next to her brother's knees. "Did I do good?" she asked almost desperately. "Go clean yourself up," he refused to praise her. Obediently she rose to her feet and left the room, walking gingerly if not a little bowlegged. I could not believe that the pretty girl all of our friends fantasized about was really a brother fucking slut but the proof was right in front of me. To be honest, I was a little disappointed in her. It took me a while to muster the effort not to be embarrassed when addressing Steve. We had both just seen each other's cocks after all. "What the hell was that about?" I asked finally. "She's real good, isn’t she?" he snickered. "She's your sister," I argued. "That's actually why," he admitted. "We've been doing this for years, long before I knew what it was exactly or that it was wrong to do it with your sister," he explained. "How did it start," I was admittedly curious. "I accidentally found one of dad's pornos. It was one of the rough abusive videos where the girl gets slapped and spanked and everything. I watched it every day when I was younger. Finally I just had to try having real sex and of course Sarah was the closest girl. I showed her the video and convinced her that girls don't get to say no when a boy wants to fuck them. To this day she still only does this because she thinks it's the law." "Are you kidding me? What would happen if a boy from school asked her to fuck with them?" "I suppose she'd probably let them." Steve shrugged. "Hell, she'd let you fuck her if you were forceful enough." "Have you let anyone else do that to her?" I asked sadly. "Not yet." He shook his head. "As she said, she does not even give blowjobs. All I've really ever did was cum inside her. She only started enjoying it recently. Before she used to scowl and say she hated me." "You're a horrible brother," I spat at him. "Who's the one that just skull fucked my sister?" he countered. "Why though?" I asked. "Are you getting sick of her?" "No, she's a real cutie so I doubt I'll get tired of her but the more I do this the more likely I'll get caught. I'm thinking of getting a real girlfriend but before that, I've got to pass her off to someone else so she won't get possessive or worse tell our parents." "And that person is me?" I asked in disbelief. "You're a good guy and I know you like her. She's in the shower right now. If you show her you're the boss, she'll do whatever you say. Go make her yours." At that moment I had several options. I could have gone home and forgotten the whole thing, potentially leaving Steve to find a different guy to fuck his sister for him. I also could have told his parents or my parents or even the teachers at school. I risked admitting being a party to the crime then. To this day I still don’t know if I made the right decision. I walked out of Steve's room and went straight for the upstairs bathroom. The shower was already running. Sarah screamed when I pulled back the curtain but I shut her up by kissing her. Eventually she pushed back though. "Stop, what are you doing?" she pleaded. "You know you don’t have a say in this," I decided to see how much she really believed Steve's lie. Reluctantly she nodded, dropping her arms to her sides. She was completely exposed, naked and ripe for the taking. All traces of our earlier escapade had been washed away. I was going to thoroughly enjoy doing anything I wanted to her with her brother's full permission. Most guys have to work hard to earn a pretty girlfriend. I had mine handed to me. She was a little used but one look at her and I knew it did not matter. She was going to do anything I asked; the perfect obedient slut.