I woke up with a start. Something was not right. I sat straight up and hit my head on the bunk above me. Cursing, I rubbed my head and looked around.

“Jake?” asked my sister from the bunk above me. “Are you okay?”

“I'm fine,” I said gruffly. “Something just woke me up.” I felt around. “Hey, what happened to my shorts?” I had gone to bed wearing a pair of athletic shorts, but I was now completely naked.

“Your shorts?” asked Sinead. “I have no idea.”

I felt around in my bunk, but they weren't there. That was weird. “I'm going to grab another pair,” I told her. “Shut your eyes, I'm getting up.”

That was the annoying part of sharing my room with my younger sister. Sharing a room with a sibling of the same sex is annoying enough but sharing one with Sinead was downright awkward. Not that I didn't like Sinead- we were very close, always had been. But neither of us ever had any privacy, and one of us had to cover our eyes every time the other was naked.

It didn't help how attractive Sinead had become, either. I mean, she was my sister, but I couldn't help noticing nonetheless. She had wavy light blonde hair which came about to her shoulders. She had stunning bright blue eyes. She was very slim and in fantastic shape from high-school track and volleyball. She had medium-sized B-cup breasts and a beautiful ass. Her smile could knock every man out who saw it.

My relationship with my sister had never been entirely platonic, although I don't think any brother and sister who are close can say they don't occasionally experience some sexual tension. She was a lot younger than me- she was 17 and I was 24, so she had started developing into her beautiful self while I was in college. I lived at home to save expenses, and I can't say that sharing a room with an adolescent girl- even one as naturally sweet and innocent as my sister- was much fun. But Sinead had made it past this stage in her life and was now a young woman, a senior in high school. She was the most popular girl in her class, I had heard. I knew she could have any boy she wanted, but she chose not to, which I admired.

“Jake, I can't get to sleep,” Sinead said from above me. “Do you want to watch a movie?”

“Sure,” I said. “What do you want to watch?”

“I just borrowed this horror movie from my friend Alicia. It's called Brother's Bite. It looks terrible. Should be fun.” She got up and threw it into my xBox. I noticed that she was wearing a black tank top and white shorts. Her blonde hair was in two braids.

“Come up here and watch it with me,” she told me. I climbed into the top bunk and sat down next to my little sister. She had a poster for Band of Horses behind her. One of the things that kept our friendship going was that sometimes, we almost seemed to be the same person. We listened to all of the same music, liked all of the same movies, enjoyed many of the same things. We both played acoustic guitar, we both ran. We even looked alike- we both had light brown hair, we were both short and slim but athletic, we both were often mistaken for being younger than we were. It was easy to tell that we were brother and sister.

The movie started. It was about a guy who gets possessed by a demon or something, and then runs around biting the jugulars of all the members of his own family, and his sister tries to stop him. I guess. I wasn't really paying much attention to the movie. I was paying attention to my real little sister, whose head was resting on my shoulder.

“Promise me,” said Sinead, “That if a demon ever takes over your body for the forces of evil, you won't try to kill me until you've wiped everyone else out.”

“Sinead, you know that's a promise I can't make.”

She looked up at me, smiling her beautiful little playful smile. “Why not?”

I grabbed her arm. “I will destroy you... and everyone who contains your foul blood,” I said, in a fair impression of the brother in the movie.

Sinead giggled as I grabbed her other arm and leaned in towards her to pretend to bite her jugular, once again as per her movie. As I was staring into her face it hit me again how beautiful she was. Her light brown hair was messed up around her head and full of static electricity. Looking into her face was a little like looking into a crazy mirrors in a hall of wonders, if there were a mirror that made one look like a very attractive woman. Light colored freckles dotted her cheeks, and her piercing blue eyes seemed to bore into me. But the smile was the best part. I loved her smile.

I reached in towards her neck and pretended to take a bite. She gave a little scream and then giggled. She then wrapped her arm around me and we continued watching the movie.

I suddenly had a crazy urge to kiss my little sister. I didn't want to just kiss her, in fact- I wanted to grab her, touch her, fuck the shit out of her, everything. I had had these urges for a while. I think it was since I moved back in. Right after college, about two and a half years ago, I had gotten a good job with an advertisement agency and moved into my own apartment. I was happy, but I missed Sinead a lot. We talked every night on the phone.

According to my parents, she cried herself to sleep every night. I felt guilty, but what could I say? I was moving on with my life. I even got a girlfriend, Amanda. I haven't had many girlfriends. Living at home during college preventing me from meeting a lot of new people, and Sinead always filled the feminine role in my life. I lost my virginity to Amanda at the age of 22, and quickly made up for lost time with her.

Then the recession came, and I was laid off. Amanda dumped me, and I moved back into this room with my sister. It was then, around a year ago, that I had first noticed an attraction to her. She was sixteen, impossibly innocent, and gorgeous.

Now, staring at my sister, I realized how completely I had fallen for her. I loved not only the wonderful things about her- her smile, her sweetness, her body- I also loved her imperfections. I had lived in the same room as my sister for fifteen years- her whole life except when she was a baby and the time I moved out- and knew her as well as anyone. But I loved her just the same.

“Harry?” came a voice from the TV. The sister had somehow arrived in a dark wooded area and was calling the name of her brother. Something scary was obviously about to happen.

“Hold my hand, Jake,” whispered Sinead in a scared voice. I grasped her tiny hand just as the brother from the movie jumped out from behind a rock. Sinead screamed, squeezing my hand tightly. When the scene was over, my sister released my hand, instead resting it on my lap. My dick instantly became hard. I looked at her but she appeared not to have noticed. God, I wanted her. I wanted to just tell her how I felt. But I couldn't.

We sat like this for a while. The movie progressed to a scene where the brother- rabid, insane, and murderous- was locked in a cell. The sister was talking to him, almost crying.

“Harry, I don't understand. Why would you do this?”

“I will destroy you. I will destroy you.”

“You're my brother! You're supposed to look out for me!”

“I will destroy you.”

“Harry, remember all of our good times together? Remember Florida?”

“I will destroy you. I will destroy you.” He lunged at her suddenly. Next to me, Sinead screamed, grabbed my hand, and started to kiss me.

At first, it was just impossible to think straight- my beautiful sister's lips against mine, her long blonde braids in my face, her blue eyes full of passion. Then several thoughts filled my head all at once:

1. Oh my God! It's finally happening!

2. Wow, she is really good.

Really, really good.

3. I'm making out with my sister. What is wrong with me?

4. Does she mean anything by this?

Our mouths opened and our tongues collided, then explored the insides of each others' mouths. If she had never done this before, she was a natural. She moved her body a little closer to me and began pressing her body against me. But I felt like before we went any further that we needed to talk. It took a huge amount of effort, but I pulled away.

“Listen, Sinead, I love you,” I told her. “I always have. You're beautiful, and awesome, and I want to be with you. But if we do this, you know we can never go back to being brother and sister.” I had rehearsed this speech in my head dozens of times.

She smiled. “You're the only man I've ever wanted,” she said. “I've been waiting for you to be ready for me for a long time.”

“You've just been waiting this whole time?”

“Well, not exactly. I've played with you when you're asleep a couple times. Here's your shorts back.” She handed them to me.

“Oh my God, Sinead.” The full reality of this was setting in- that she was no longer my sister, but my girlfriend. It occurred to me how suited we were for each other, how similar our interests were, how well our personalities matched. It seemed almost as though we had been made for each other, even if we were brother and sister.

Sinead pulled the pair of shorts I was wearing down. My dick was fully erect. She licked the very tip. It twitched a little and she giggled. She licked it again and gradually moved her mouth around it. I let loose a deep groan as she began sucking. I had no idea how she had gotten this good. I couldn't hold on. Within thirty seconds I came deep into her mouth. She swallowed every squirt, and then pulled away and licked her lips.

“You came so much,” she said. “I didn't know that much was even possible.”

I kissed my sister on the lips. She responded by leaning over and necking me, leaving a giant hickey showing.

“Listen,” she said. “Mom and Dad are going out of town tomorrow night. What time do you get off work?”

“Eight o' clock,” I told her. “Why?”

“You'd be here then,” my stunning sister told me. “You wouldn't want to miss it.”

We flipped the movie off. The brother had broken out of his prison and was on the loose now, but neither of us really cared what happened next. I climbed back down to my bunk and tried to fall asleep.

All my dreams that night were of my sister. When I was working at the fast-food restaurant where I'm employed, she was all that was on my mind. I couldn't concentrate on anything except for her.

There was a late rush so I didn't get done with work until 8:30. I rushed home going twenty miles per hour over the speed limit and flung the door to my house open.

“Hello?” I shouted. There was no response. Music seemed to be coming from me and Sinead's room.

I rushed over and opened the door. There, sitting on her bed, was Sinead.

I have described my sister's beauty previously in the story, but it was nothing compared to the way she now looked. She had her luxurious blonde hair down around her head and was wearing just the barest hints of makeup. Her blue eyes were sparkling. She was wearing a low cut strapless black dress which showed off her spectacular body. I'm amazed I didn't ejaculate just from looking at her.

“You're late,” she said. She didn't sound mad. Her eyes were shining. She hopped down from her bed and approached me. She kissed me lightly and I took her in my arms. We began to dance.

I swayed my sister back and forth as she pressed her body against me. What we did quickly transformed from dancing to feeling each other up rhythmically.

I couldn't take it anymore, I unzipped her dress from the back and pulled it down. She wasn't wearing a bra or panties underneath. She grabbed my pants and pulled them down as I ripped my shirt off. We fell into each others' arms.

After a few minutes of fondling, my sister asked me, “So, do you want to go all the way?”

“What? Sure... if you want to.”

“It's the only thing I've wanted for a long time.”

I kissed her and she laid out on her bed. “I broke my hymen for you the day you moved back in,” she told me.

“Well that'll save me some work,” I told her. I climbed on top of her and prepared to fuck my own sister. I put my cock in her pussy and she gasped.

I started out slow. Her pussy was wonderfully wet and tight, and her moans increased in rapidity as I fucked her harder. Her blonde hair was spread out on the bed. It was the most incredibly sexy thing in the world to think that this beautiful, incredible young woman was, in some sense, mine. She was my girl. My Sinead.

We didn't last long, maybe a minute. It was she who orgasmed first. It turned out that my little sister was a squirter. My lower body was drenched with juices. Then, a split second later, I squirted my load deep inside of her. We laid there for a while, just panting.

“So,” I asked my little sister. “You up for round two?”

“I'm ready for a million more rounds, but are you up for it?”

“I will destroy you.”

She mock-slapped me as we headed out of our bedroom. We went straight for the kitchen. “You want to do me on the table?” she asked.

I pointed to the porch. “Let's do it out there.”

“Are you kidding? Everyone will see us.”

“It's nine o'clock at night.”

“Well everyone will hear us.”

“I want them to hear.”

She smiled mischievously. “Let's do it.”

I sat down in one of the deck chairs and she climbed on top of me. The top of her head was right in front of her chin. I breathed in the scent of her hair and was instantly as aroused as I had been before. She sat so that my dick was right in front of her pussy. With a couple hops and loud moans, I was inside her once more. I started to fuck her on the chair, against the table.

“Oh... oh.... OHHHH!” She was moaning so loud I was amazed that our neighbors weren't hearing us. I pressed my body against her and felt the sheer ecstasy of fucking a beautiful woman, a beautiful woman in my family, a beautiful woman in my family who I had been in love with for almost half my life. As we continued, I picked my sister up by the waist and carried her to the railing at the edge of the porch. She grasped onto it for dear life as I rammed her a last few times. Then, suddenly, her pussy tightened again and released its juices. I squirted once in her and then removed my cock. I covered her ass, her back, and her chest with my cum before collapsing exhausted next to my sister.

The doorbell rang. “I'll get it,” said Sinead. She ran over, still naked, and opened the door in front of her, so that only her head was visible to the person there. Our neighbor, elderly Mrs. Jones, was standing there.

“I thought I heard some loud noises coming from over here,” she said. “Is everyone all right?”

“Completely alright,” said my little sister. “Never been better.”

An hour later, we were lying naked on the floor together, watching the end of Brother's Bite. The brother had the sister cornered. The sister was holding a shotgun.

“Get away from me, Harry! I swear I'll shoot!”

He made a loud grunting noise. “Destroy you” was audible in there somewhere.

“Listen Harry, I know you're possessed, but my brother must be in there somewhere. Harry, why are you doing this?”

The possessed beast seemed to be having some kind of internal struggle. “Susan?” it finally asked.

“Harry?”

It paused then lunged at her. I heard sounds of ripping and tearing from the television, but I never saw how the movie ended. During the scary scene, my sister had grabbed me, and we made passionate love on our floor twice more. By the time we were done, the credits were rolling.