Chapter 1

Caution: This Incest Sex Story contains strong sexual content, including mt/ft, mt/Fa, Teenagers, Consensual, Romantic, BiSexual, Heterosexual, Fiction, Cheating, Incest, Mother, Son, Brother, Sister, First, Oral Sex, Masturbation, Petting, Slow, .

Desc: Incest Sex Story: Chapter 1 - My name is Matthew Keating, and I’ve lived a life that most people would, charitably, consider… unconventional.

My name is Matthew Keating, and I've lived a life that most people would, charitably, consider ... unconventional. In fact, the average person would most likely call me a sick pervert, a deviant, a criminal, maybe even a sinner, destined to suffer for all of eternity in the very bowels of hell.

Don't misunderstand me, I don't share that particular low opinion of my worth.

Though I've certainly made some unusual choices in my life, which have led me down seldom traveled paths, looking back on the years now I know that I wouldn't change a single damn thing. My life might be abnormal, but I have never hurt anyone, directly or indirectly. If I truly had to describe my life, it would have to be "one hell of a fun and fulfilling time".

It all started when I was seventeen and spending the summer at a small family reunion at a lakeside resort.

No, wait ... I really should start further back. Give you some more context to my family and the whole extraordinary situation I somehow found myself in.

Or maybe, I subconsciously created it?

The one thing I am sure of is my whole life started to change, quite innocently enough, because of my little sister Andie.

We were a run-of-the-mill middle class American family. Just two parents and their two kids living in a nice house in the suburbs. My dad, Steven, was a mid-level executive at an insurance company, while Amanda, my mom, was a part-time administrative worker at the local elementary school. We were a pretty happy family, but things would eventually change and become much more ... complicated.

We would still be a happy and loving family, just a very unconventional one.


One early morning, when I was fifteen years old and Andie had just turned thirteen, I stumbled into our shared bathroom, still bleary-eyed with sleep. There, I was surprised to find her bent over the sink, brushing her teeth. She had apparently forgotten to lock the door connected to my bedroom.

All pretty harmless and ordinary, right? It happens to siblings every day, all over the world! I know it was a pretty common occurrence in our home – Andie and I had been sharing a bathroom for some years, ever since we moved into this house. Despite the occasional argument about who got to use it first and for how long, we had gotten more or less used to it.

This time was different though. By some strange twist of fate, this time we were both only in our underwear.

We were a pretty laid back family. No one thought anything of crossing the hall only in their underwear, or with nothing but a towel wrapped around them, for example. But, ever since starting puberty, Andie had been terribly body shy, especially around me and our father. Typical teenage girl behavior, I'm led to believe.

This was the most of her skin that I had seen in a couple of years.

She was wearing a plain, light pink bra, but she hardly needed it, having only the barest hint of breasts. Her matching pink boy shorts seemed to be a size too small, clinging tightly to her nicely curved hips and nice tight ass, revealing every fold and crevice in startling detail. She was bent over slightly, leaning forward to examine her reflection in the mirror more closely, her back arched attractively. This displayed her long firm legs, round, upthrust peach-shaped ass, and her tightly covered mons to perfection. She was slim and petite, taking after the women on dad's side of the family, and quite fit and athletic, the obvious result of her love for soccer and volley ball.

Her vigorous tooth brushing, with a drip of white toothpaste foam on her chin, was more than just a bit suggestive. Not only that, it was also making parts of her anatomy shake in very interesting and incredibly distracting ways.

'Damn, she looks good, ' I couldn't help thinking, feeling incredibly surprised - it seemed that just a short while ago Andie was a rail-thin and gangly tomboy. 'When did she get those damn curves?'

Likewise, I just couldn't help the massive hardon that jumped up quite suddenly and forcibly within my boxers.

Admit it people! Every man goes through this embarrassing realization some time or another in his lifetime. Even a few women, I'll willing to bet. A moment when they realize that they are sexually attracted to someone they definitely shouldn't be – namely, a family member. If they don't have a sibling, it'll be a cousin, an aunt or uncle, or even one of their own parents. Maybe it's an in-law of some kind, or if they're older, a child or grandchild. It doesn't mean that they'd actually act on those feelings, but they're there and they're absolutely unavoidable.

Plus, admiring and fantasizing never really hurt anybody.

I really should have known better. I should have swiftly and silently retreated back out to my room, but I just couldn't tear myself away from the sight before me. Maybe it was just the light she was in, or the fact I hadn't actually started dating yet, but no high school hottie or internet porn babe had ever gotten me so turned on, so quickly.

Andie hadn't noticed me entering the bathroom, nor had she noticed me studying her body intently for the past couple of minutes. But, as she shifted her stance and pulled her long black hair over one shoulder, she finally noticed me in the mirror. I watched her reflection intently as I tried to keep up with the rapidly shifting emotions I saw there. First her eyes widened and her mouth fell open slightly in surprise, leaving her toothbrush dangling slightly. A reddening that started in her face and spread over most of her neck, shoulders and chest revealed her embarrassment. Then I saw fear, confusion and a touch of anger warring each other equally in her expressions and posture.

Only then did she seem to notice that I was just as exposed as she was. Her expression softened distractedly a little as her eyes traveled down my naked chest.

I fully admit to being embarrassed, but only slightly. Besides the courage lent to me by the pure animalistic force of my arousal, I'm happy to say that I was pretty proud of how I looked. Though just a couple of years ago I had been slightly on the pudgy side, playing lacrosse at school, the occasional home workout and a summer job as a stock boy at a local supermarket had all seriously improved on my build. I was far from being ripped, but my stocky frame was certainly well muscled.

So, I let my sister take me in, honestly enjoying the admiring attention. I just managed to keep myself from striking a pose or flexing.

Eventually, her gaze reached my tented boxers. Her eyes widened once again as she stared intently at my covered hardon in the mirror's reflection. It was quick, but I saw her small pink tongue dart out of her mouth and lick her lips and my erection jumped in response. Looking at her chest, I saw two prominent bumps slowly appear on her bra just as I heard a sharp intake of breath.

I couldn't keep the small smile off my face. Clearly I wasn't the only one enjoying the view.

We stared at each other like that for some time, neither one of us moving a muscle. Only our eyes moved as we took in each other's bodies. Looking back at it now, I'm still unsure how long it was - it sometimes seemed like mere seconds, at others, whole hours.

Finally, Andie looked away, breaking the spell.

She calmly spit into the sink, rinsed her mouth and put her toothbrush away. Brushing her hair behind her ears – a nervous tick of hers I had always been fond of - she then turned around, facing me directly. Though she tried to look me in the eyes, they kept shifting down towards the obvious and bobbing bulge in my boxers.

"Perv," she called me, trying in vain to hide the amused smirk on her face.

She then casually walked out of the bathroom, her head held high, taking her sweet time about it and with a noticeable extra sway to her hips. I tried the best I could to burn the image of her flexing, tight ass checks into my memory. I didn't know when I'd ever see it quite like this again, after all.

And that was "The Event" which started it all.


Andie gradually gained some self-confidence, no longer embarrassed or reluctant to reveal her body. At least not around me. She started buying and wearing tighter and more revealing clothing – nothing over the top or slutty mind you, that wasn't her style. Just attractive, flattering and sometimes drop-dead sexy clothing. She even started using a little bit of light makeup.

Looking back now, I know that she was actually enjoying flaunting her budding body and testing the power of her sexuality on a completely safe, but obviously very appreciative audience.

Even her social life improved. She had always been a bit of a tomboy and a geek – just like her big brother – eschewing most of the typical preteen girl preoccupations with fashion and cosmetics. Which, unfortunately, tended to alienate her from a lot of the other girls her age. Embracing her femininity and sexuality gave her a much appreciated popularity boost, widening and diversifying her circle of friends.

I had ... mixed feelings about the whole thing.

Sure, I was glad that she was happier and more outgoing. I certainly appreciated the occasional presence of some of her new and very attractive girl friends around the house. It was the guys that I had a problem with – the ones who couldn't help but cast admiring glances all over her firm, maturing body.

Protectiveness was at the core of what I was feeling, but I'd be lying if there wasn't also a good bit of jealousy and possessiveness at work.

She was still too young to be allowed to date, but I was pretty sure that she had a way around that little fact. I didn't know what kind of "experience" she had gained and I really didn't want to know.

I'd probably just end up killing some snot-nosed punk in a fit of blind rage.

Our morning encounters in the bathroom became almost daily events, which I quickly learned to look forward to. Every time she'd be dressed in a different outfit – from simple nightshirts and silk pajamas, to swimsuits and bikinis during the summer, but all-in-all, bra and panty sets were the most common and varied. I know that she didn't actually own that many pieces of clothing, so I suspected that she was constantly borrowing or trading with her friends.

It sure as hell beat baseball cards, in my humble opinion.

Before even opening the bathroom door, I found myself already erect in anticipation. Afterwards I'd then have to jack-off in the shower, before being able to head downstairs for breakfast.

Over some time it even evolved to encompass situations outside of our shared bathroom. For instance, she would let things drop around me, so that when she bent over either her firm and enticing ass would be pointed in my direction, or an impossible to ignore view of her slight cleavage would be in my face. While sitting or lounging around the house, while wearing a skirt, I could expect to be treated to the sight of a generous expanse of smooth thigh, sometimes almost reaching her panties. Walking down the hallway on any given day, there was a good chance of catching a glimpse of Andie changing clothes through a slight crack in her bedroom door that she had conveniently "forgotten" to close. Sunning herself in the back yard, wearing one of her barely there bikinis (which she made damn sure to hide from our parents), she'd slowly rub sun block all over her exposed skin, again and again, certain that I was there, taking it all in.

And these were just a few of the most common encounters which she arranged.

It became an exhibitionist game to her, seeing how long, how many times and in how many different places and situations she could catch me staring at her and get me hard. Whenever she'd see the familiar bulge in my pants, she'd simply look me in the eyes and give me the same happy and proud smile. If we were alone, she'd playfully call me "perv".

It was a game that I dearly loved to play.

Outside of our little, secret game, we continued to act just like any other normal brother and sister. Our sibling relationship was pretty damned pleasant – we'd both outgrown the "I hate you" phase a couple of years ago and had become reasonably friendly. We occasionally played together, picked and teased each other, often got on each other's nerves, talked and joked with one another, and we even had the rare loud argument.

An outsider would never have been able to guess just what we were both thinking about while we anxiously looked into each other's eyes.

But for some reason, by some unspoken, mutual agreement, we never talked about The Event or our Game. I had no idea what she thought or felt about me or the situation. She genuinely seemed to enjoy it, almost as much as I did, but I couldn't help but feel the occasional pang of worry and guilt.

Was I somehow taking advantage of her, or causing her real, lasting psychological harm?

No ... I couldn't believe that.

Although we never actually discussed it, I knew that we were both consenting and enthusiastic participants.

But still, I worried.


Seeing as a face to face conversation with Andie would be just too damn awkward, I decided to go another route.

One night when I was in my room, our parents were downstairs in the living room watching TV, and I was sure she was on her computer in her room, I sent her a message using a secure LAN chat program. We two were the only computer literate people at home and the program was very minimalistic and completely secure, so I was sure that there was no danger of "eavesdroppers".

Matt - Hey sis, how ya doin?

I waited for her to notice the window that had just popped up on her screen and respond.

Andie – ummm good u? lol y r u msging?

Her surprise and confusion was understandable seeing as I had installed the program and set up her account all without her knowing.

Matt – Good! I'm messaging because we need to talk and I thought it would be easier this way.

Another long wait. The few moments it took for her to answer seemed like an eternity.

Andie – wat do u want 2 tlk bout?

Matt – You know what ... our bathroom dates and this teasing game we seem to be playing. I just think that you should know that I love it.

My heart was pounding in my chest – the excitement and nervousness was almost overwhelming. I had no idea that just chatting with her about this would affect me so.

Matt – You are a beautiful girl, who's quickly becoming a gorgeous young woman. I can't help but stop and admire your hot body whenever I see you. I truly hope that you're OK with all this.

A long pause again. I actually started to tremble with anticipation.

Andie – course im ok with it! i rely like that u find me sxy:) it's a rel ego boost. + u r prtty hot yrslf ;)

I stared at the computer screen for several heartbeats, my cock now rock hard. Not only was she good with our Game, but she was genuinely enjoying it. Any and all remaining guilt that I might have been feeling simply evaporated.

And easy as that, the lines of communication were opened between us. Almost every day in the evening and night, we'd spend a few minutes to hours chatting, becoming incredibly close. We'd talk about our days, school, our parents, joke around, discuss our dreams and goals ... but above all we flirted shamelessly. Never anything too graphic, but still suggestive as hell.

I even commented on the outfits and poses she had "presented" for me and I quickly noticed that she started focusing on those which I liked the most.

My sister was purposely dressing to turn me on!

Chapter 2 »