It all started one warm summers day. My life had been pretty ordinary up until that point. I had no idea my life was going to change so dramatically.

I live in a quiet neighbourhood in a quiet town. I have a pretty nice house and live with my mother and my older sister, Becky. My dad left years ago so it was just the 3 of us. My mom spent most of her time a work so I was quite close with my sister as it was often just the 2 of us at home.

I was still a virgin but had been with several girls, I just never got that far with them. I was pretty shy and pretty average looks and build. My sister was a different story.

My sister had always been very outgoing. She was popular and got plenty of attention. As we both got older I began to see her in a different way. I realised how pretty she was and later on, what an amazing body she had. I felt confused and embarrassed when I got turned on around her. I got hard more than once watching her swim and sun bathe in her bikini or walk around the house in just a towel or her bra and panties. It felt wrong but it didn't stop me from jerking off thinking about walking in on her taking a shower or changing.

Unlike me she was definitely not a virgin. She'd had a few boyfriends and I knew she had been further than me.

One night she had gone out to a party at a friends house. My mom was out of town that weekend and it was just me at home. I was in bed when I heard the front door open. I heard her and a boy speaking downstairs.

"Shhhh!" She said much louder than she intended "don't wake my brother. Its just him at home but he's a heavy sleeper, we won't wake him" I listened to them for a while. They both sounded drunk as they climbed the stairs. It was lucky I was the only one home because they were not quiet.

I quietly got out of bed and peeked out of my room. I saw a trail of clothes leading from the top of the stairs to my sisters open door. My sisters bra and panties were laying directly outside my door and a pair of boxers were not far away.

I began to walk silently back to my bed when I heard noises from my sisters room. Our room were right next to each other's with the beds on either side of a thin wall. By the time I was back in bed I could clearly hear my sisters bed creaking and it wasn't long before I heard her moaning in pleasure. I lay in my bed for what seemed like hours listening to my sister lose her virginity.

I couldn't deny that listening to my sisters gasps and moans wasn't turning me one. After a few minutes of my sister getting pounded I felt my hard on straining against my boxers. I couldn't stop myself any longer, I stripped off and took my shaft in my hand and stroked myself thinking of my sweet sister taking her first cock just on the other side of the wall.

I imagined taking her as I listened to her strained moans and listened as her moans got more desperate and the bed creaked even louder. I felt myself explode as she cried out and I knew she was cumming. I lay back on my bed, naked, and thought about what had just happened as I drifted off to sleep.

I awoke the next day to the sound of the front door slamming closed. It took a moment for me to register what had happened last night and decided to go and clean myself up.

I pulled on my boxers and left my room. I realised that my sister's clothes were still laying on the floor but the boy's were gone. Before I reached the bathroom I realised that my sister's door was still wide open and I'd have to walk past it to get to the bathroom. Curiosity got the better of me as I snuck past her room. I looked in and saw my sister lying face down and naked on her bed. Her blanket lay across her lower half covering her butt but I still saw her toned legs and her bare back with her beautiful long hair covering her shoulders. She was alone, her friend must have snuck out.

I resisted the urge to venture further into her room or to take a photo. However, I couldn't resist jerking off in the shower thinking about her amazing body and what I'd heard last night.

Once I'd finished in the shower I headed back to my room. I walked past my sisters room and I noted that her clothes had been recovered and her door was closed. I made it back to my room and cleaned up the mess before getting changed and heading downstairs.

I sat down in the living room and switched on the TV and tried not to focus on what had happened. What happened next didn't help.

I heard footsteps and turned to see my sister coming down the stairs. My jaw must have hit the floor when I realised she was just in her underwear.

"Oh, hey" she said "I didn't think you'd be up so early"

"Well…I…errrrr" I stammered.

"What's up with you?" She asked as she disappeared into the kitchen.

Much to my discomfort she stayed in just her bra and panties for several hours. She seemed pretty happy and didn't seem to notice that I could barely keep my eyes of her.