For starters, my name is Jack. I've attended the same school, Southeast Smith Northwestern, for my entire childhood. There isn't much to know about me, not much different from your average guy. I like reading, sometimes, I love video games, I watch a lot of porn and masturbate plenty. I wasn't sexually active at the time of this story. Not yet, anyway. But I had just turned seventeen, and I've never been one to break a law, even if I didn't much like it.

I guess who you really ought know more about is my sister, Katie. I've always felt bad for her because even though she looks so good, she attended an all girl's school and never had a boyfriend. Katie and I are only a little past nine months apart. Nine months and 14 days. Our parents had gotten frisky on their anniversary a couple weeks after I was born, I guess. I had always thought that wasn't fair to me as a baby, but my upbringing was more than I could ask for, and is a good example in my own mind as to how a child should be raised. Katie, though not even a year younger, has some severe disadvantages over me. Firstly, she isn't built very... Heftily. She's been small her whole life, in most places. She only reached 5'3, but that was when she was 15, and she's done growing now. She has a great metabolism, or so I assume, since she's eaten plenty but always maintained a desirable shape. Those are the only two categories she's lacking in though, for certain. I really have no idea her bra size, since it's none of my business, but they're wonderfully large by comparison to the bustiest girls at my school.

Katie and I have always been as close as brother and sister can be. We have never had big problems with each other. No big fights, no difference in many preferences. We enjoy the same kind of music, which is really nice. Whenever we take a road trip I'll hook up my iPod and we can all enjoy the music. Katie has always needed a male role model in her life, and I've definitely taken on that responsibility. Our father was actually a wonderful man. While we still knew him, we loved him endlessly. He was incredibly kind to us and would always be there for positive encouragement. Just that fact meant I wasn't surprised when he was drafted, but I had no worries either. Daddy was big and strong. But others were bigger and stronger, and we one day received two letters. The first from him, telling us he'd been shot in the lung, and didn't know what would happen. The second a confirmation of his death, and an explanation as to why the first letter wasn't immediately sent due to his passing moments after. We were all crushed. But 6 years later, life has not let us down again, and moving on was made easy by our wonderful mother.

Katie and I have had a kind of relationship you'll see very rarely. It can be somewhere between platonic and intimate without being creepy or awkward. We hug and cuddle quite often, but I've never had any sexual thoughts about her.

But one night, she came home crying. A boy she'd met at a party a few weeks ago who had seemed to take interest let her down, harshly. She ran into my room, as was customary in her emotional moments, and collapsed into my now open arms on my bed. I gave her some time to gather herself before I encouraged her to explain.

While she was sobbing, I noticed something I hadn't before. Her breasts had gotten much larger recently, in lieu of height, and for some reason felt nice against my chest. I told myself it was stupid, but I was gaining a slight hard-on that was making me guilty.

I ran my hands up and down her back to calm her down, stroking her beautiful hair. I had always thought her hair has beautiful, but the recent summer highlights of blonde in her brunette curls were natural and gorgeous, tied back into a medium length ponytail. Again, I felt guilty, but decided I shouldn't. My sister was beautiful, and I knew it. I had always known it.

Finally, she had calmed down enough to speak. She pulled her face out of my shoulder, and I saw her in full make-up. I suppose it was waterproof, because only her eyeliner had run at all, and only very slightly. I realized again, she looked stunning. Her soft, blue eyes, shiny with tears, looked into mine, and her bright pink lips managed a slight smile.

I stretched myself across my bed to the tissues, whish she was having trouble reaching. Since I have a whole foot on her height, it was easy for me. Even my arms were monstrous in comparison to hers. Her small, light-brown tanned arms and legs, with a perfect tan line... She gladly took a tissue and cleaned off her face. Then we started our discussion.

She gave me a quick hug, and held both my hands with hers. After a sniffle, she said "Thanks, Jack. Just you holding me like that makes me feel better."

'Makes me feel pretty damn good too,' I thought.

"Of course," I said, "nothing makes me happier than knowing I can cheer you up. Now tell me your dilemma this time around."

Katie went on to explain what had happened. I had become rather good at getting the gist of what she was saying through her huge amount of pointless details, and could usually tune out and still know the whole story in the end. But this time, instead of daydreaming about video games or a girl from Southeast, I found myself looking at her a lot more. She was, even in this disheveled and upset state, gorgeous. She was wearing relatively tight clothing that showed off her ass when I could see it, and really accentuated her huge breasts. Her amazing hair was... Well, still amazing. She suddenly took it out of its ponytail and brushed it to one side, which for whatever reason drove me crazy. I wanted to grab her right there and show her what passion was all about, I could squeeze those breasts and that little ass, and... 'Oh my God, what am I thinking?' I was being ridiculous. This daydream was way inappropriate, even for a personal thought. I could tell by her tone that she was reaching the end of her story, so I tuned back in.

"Then Dahlia said he was a jerk anyway, and wouldn't have been any good as a boyfriend, but it was just the hope that got me so excited, I guess."

"I'm sorry, Katie.

If you didn't even know this guy, why would you think anything of him?"

"I don't know... I guess I've just been tired of lesbians hitting on me and wanting some guy to be there for me. I've waited so long for some love, and haven't gotten any."

"Well I love you Katie, and even though it isn't the same, I know everything will turn out fine. Forget that piece of shit, if he really led you on like that."

Katie sniffled, then got it together again. "Thanks, Jack. I love you too."

I kissed her head and let her lay on my bed while I finished packing up for school on Monday. I didn't have big plans for the weekend, but I was still excited to be out of school. It had been a long week.

When I got back to my room, Katie had fallen asleep on my bed. This wasn't unusual, and I did what was expected, and carried her to her room. Katie was a heavy sleeper after she had been crying, so I knew I could get her into bed no problem. Once I had her in her room, a thought came to me.

'She's wearing dress clothes. They'll get wrinkled if she sleeps in them.'

The thought was random, but something in me wanted to agree, so I decided to get her into pajamas. I grabbed a set from her drawer, but a glimpse of her underwear set my mind off again.

'This is ridiculous!' I thought. 'I can't keep thinking about her like that.'

My conscience settled with itself at last, and I decided to just get her into pajamas and go to bed myself. I removed her pants and replaced them without temptation, but knew a battle with conscious ethics would take place with her top. I was determined to resist though, and got her pajama tops out. Then I carefully unbuttoned her top and took it off.

'Holy shit!!!' Katie wasn't wearing a bra under that top! Her amazing rack was on display for spectating, and I finally gave up my morals to get a premium pass view. I didn't touch, but I got two eyes full of her pointed little nipples and humongous tits. I had thought they were huge before, but she was certainly trying to cover those babies up. I stood with my mouth agape for a few seconds, before my conscience finally got the best of me. I slipped her into her pajama tops, and took off her shoes and socks, and took her earrings out too. Before I hit the light, I got another little sneak peek at her pointed nipples through her pajama top. I went to bed and jerked off, but couldn't focus on my porn. That was definitely not the source of my now incredibly huge boner, and when I came I was thinking guiltily about Katie.

The next morning, when I woke up, I checked through Katie's door to make sure I hadn't been dreaming. But Katie wasn't in her room. Knowing she had just gotten up before I had, I went downstairs. Katie walked past me with her breakfast on my way to the kitchen. She blushed a deep red color as she went by, and I wondered what was up. She was wearing the same pajamas, so that was no dream. Then it struck me!

'Oh shit! Katie knew she wasn't wearing a bra last night, and must know I changed her into pajamas! So she knows I saw her chest!'

My mind leapt for excuses or anything to cover it up, but I came up with nothing. The day passed normally otherwise though, because she went on like nothing happened.

Later that night, our mom had gone out to a club looking for a date. Katie and I both liked when she went out because it meant she was moving on from Daddy, but it also meant we got time alone together, which we both loved. We ordered a pizza and laid on the couch to watch a movie together. Once we'd finished the pizza, I realized I had barely gotten any sleep last night because I was starting to pass out. Before I knew it, I was asleep. But when I woke up, I didn't move right away, because something strange was happening.

Finally I came to my senses about what was going on. Katie has grabbed my hands, and was using them to rub and squeeze her breasts! I had no idea what was happening, but I was in no way against this. I had woken up with a huge hard-on, probably induced from this very action, even in my sleep.

Katie was moaning softly, whispering my name and grinding against me.

"Oh yeah Jack, I know you saw my big boobs. I hope you loved them, they're just for you, baby, only for you. Don't you love them? Don't you love to squeeze them and rub and play with them? I do. I do every night, thinking about you. And now you really are playing with my big titties, and I bet you love them don't you?"

Katie suddenly let out a loud moan of intense pleasure as she made me squeeze her extra hard. Realizing this was my only chance, I decided to take it.

I grabbed her tits as tightly as I could without hurting her and began to rub them and rotate and squeeze them quickly and with a good amount of force. "Oh yeah Katie, I saw your big tits and I do love them. They're so big and amazing."

Katie gasped, surprised, but it suddenly turned into a loud moan of pleasure. "Oh baby, squeeze them harder! And stick your big hard dick inside me too, I'll love that so much!"

I took off my pants and carefully reached around and helped her remove her skirt too. Then I plunged deep inside of her, and rhythmically started fucking her. I kept my hands firmly on her breasts, rubbing and squeezing and rotating them faster and harder. Katie still hadn't turned around to face me, but I gripped her tits tightly and pulled her on top of me, fucking her faster and squeezing her tits more and more, until finally I climaxed deep inside her. She threw her hands over mine and made me push her breasts tightly together, and she quickly climaxed too. She shook for a couple seconds, moaning quietly, until she finally turned over and kissed me full on the mouth. She laid down beside me, then, but before either of us could say anything, the lights went on...