I was sixteen when my adopted dad died, it happened so suddenly and our family was never quite the same. My "sister", named Sarah, was fifteen at the time and we had grown close over the 10 years I had been with the Smiths. I don't remember my real parents, I was taken off them when I was young and passed around until I settle with the Smiths. They were awesome. Treated me like there own and loved me. I never held a grudge against them for not being my real parents.
After the passing of our dad Sarah and I grew so much closer. Mum had to take up more hours at work to help make ends meet so a lot of the time; it was just the two of us. Dad was like a rock to Sarah, he was always there for her, to comfort her and make her feel better. With him now gone, I felt like it was my duty as, the new man of the house, to step up and look after her.
Over the next few years it was hard at times but Sarah and I were definitely closer than ever. We had picked up new habits with each other and were like best friends. Going out to the cinema together, gossiping with each other, even wrestling but it was always quite harmless. However things took a whole different direction not long after Sarah's 18th birthday.
I have never thought of my sister in a sexual way. Even though she isn't my real sister, I have noticed that she had grown up a lot and had some very nice assets but noticing was a far as it went. Even when we play fought and I would grab her tit and cupped her ass, it never crossed my mind that it was bad. However one late night I had gotten up to go to the loo, as I walked back to my room I stopped outside Sarah's door. The noises I heard were unmistakable, the pleasure moans of her having fun either by herself or someone having fun with her. I leaned closer to the door to hear better, I don't know why I stayed but I did. Listening closely I was positive that she was alone and enjoying it a lot. As I listened something deep inside me stirred, the sounds where turning me on.
I had stayed too long and in my hurry to retreat to my room, I banged against the door. I didn't stop to see if I was noticed or not but made my quick escape back to my room. I dived back into bed and pretended to be asleep in case Sarah came into the room, she didn't. I lay in my bed for a while and stared at the ceiling and all I thought about was hearing my her moans and how it made me feel. A flood of emotions came over me, I felt a little ashamed because she was a sister to me but I also felt horny and intrigued. With all these emotions over me it was evident which one I felt the most because I realized I now had a massive erection. "Oh my god" I whispered out, had she turned me on so much?
I struggled to sleep that night but got some rest, the next morning was a whole new challenge. I had slept in and was late down to breakfast; Sarah was already sitting at the table as our mum was busy in the kitchen.
"Oh hey there bro, finally awake are we?" Sarah smirked behind her normal morning magazine.
"Right Jamie" mum said above the noise of her washing the dishes "I need you to nip down to the post office and post that parcel for me" she nodded towards a large cardboard box sitting on the table. "Also need you to pick up my dry cleaning"
"Uuggghhh OK, anything else?" I exhaled, hoping the answer would be nothing.
"Erm" my mum paused in thought, I eagerly waited in anticipation, fingers crossed. "No not today"
"Sweet, I mean OK mum" I chuckled as I grabbed some cereal and grabbed a seat next to Sarah.
I felt a little awkward as I sat there after what had happened last night. I quietly crunched into my cereal, avoiding eye contact with her. Then she broke the silence
"So dear bro of mine, what are your plans for tonight?"
I chocked a little on my cereal before answering "eh nothing much, just chilling here most likely. What about you?"
"Nothing much either" as she peered over her magazine, "would you like to watch a movie with me then??" she smiled lightly.
"Oh I suppose, how could I resist that smile" I said sheepishly.
"Yay good, it's a date" she said jokingly.
The rest of the morning went by without any mention of last night. Mum and I, headed out of the house at the same time. She went off to work, as I set off to complete her chores. I carried them out without any issues and was back within a couple of hours. My mum was still at work and I wasn't sure if my sister was in or not. "Sarah" I shouted out breaking the silence of the house, I waited for a reply and was greeted with nothing. Thinking I was alone I grabbed a quick bite to eat and headed up to my room. As I neared the landing, I noticed her door was shut which she only did when she was in. I moved closer to her door and was met with the exact same sounds as last night. She was playing with herself again but this time the moans were a lot louder, clearly thinking that she was alone in the house. I couldn't help myself but I stayed to listen more. The deep feeling inside of me was building again and I could feel myself getting hard in my boxers. It wasn't long until I heard it, one of the hottest sounds I have ever heard, Sarah having an orgasm. I couldn't believe what I heard; I quickly snuck into my room and eased my door closed behind me. I leaned my back against the door, again in disbelief as to what just happened. I stood there for a moment in a confused daze, I snapped myself out of it and went over and set up my games console.
I had only played maybe 10 minutes before my attention span snapped and my mind drifted back to the sounds of Sarah. This level I was on was hard enough when I was paying full attention but near impossible when all I thought about was the glorious sounds of Sarah's orgasm. I switched off my game and got myself onto my bed. I lay there, trying to relax but my mind began to run. I was no stranger to woman and had heard girls cum before, not just from porn. Not saying I was some big ladies' man but definitely made a few girls cum in my time. Drifting back, I reminisced about the few sexual encounters I had. Thinking of Polly from the store and how we had a quickie in the storage room or Beth at school, where she sucked me off in the toilets. Also losing my virginity to Carly at the house party and how great that was for my first time. God knows if it was hers but it felt great to me. As I lay there, thinking of these girls, Sarah was always in the back of my mind. How she had sounded so hot playing with herself and one feeling was becoming very dominant, I wanted her and my rock hard erection proved that. With the small feeling of wrongness and shame fading, I dozed off.
I was awoken by Sarah, tapping against my door as she stood in the door way.
"Hey wake up lazy bones; you have a movie to watch with me! Now come on" Sarah teased as she darted off out of my room.
I gathered myself as I tried to come back to reality, napping during the day does that to you, and when I looked down, my sweat pants where bulging from my still rock hard cock.
"Fuck" I muttered to myself, fearing that Sarah had maybe seen it. What if she had seen it and liked it or worse seen it and was repulsed, I was kind of her brother after all. "Geez Jamie, get yourself together" I said to myself, giving light taps across my face. I managed to get my erection down to an appropriate standard and headed down stairs. Sarah was already sitting on the sofa with the movie ready to play.
"Is mum home" I asked trying to remain calm and not worry about recent events.
