Wrong!

I was old enough to know better. Clever enough to know better. Responsible enough to know better. I should have been able to do the right thing, the only thing.

This story recounts events beginning in the summer of 1994, not really that long ago, but an age before mp3 players and before mobile telephones really became popular.

I am Mark Johnson, a married, thirty two year old school teacher. Married to Sophie, thirty five, a lawyer, for six years. I have been teaching at the same school, Lakeview High School for eight years. Teaching history to year after year of school children who really aren't interested in a word I'm saying.

Sophie works long hours but the benefit is we live quite well, no money problems. No children of our own yet, our careers have been our priority. We have a very good relationship and a good sex life. We are very happy with each other's company and have experimented in various things over the years. Bondage, role playing, anal, oral - we've tried all that. We've even had several threesomes. Twice with another man, an old school friend of mine who lives far away. Four times with a friend of Sophie's, Rebecca.

All good fun, that's how we view it. Good fun, nothing serious. The main rule is that we don't take anything too seriously.

My parents live about an hours drive away. I take after my father. He was also a history teacher. He's fifty nine now. Growing up it was my parents and my elder sister, Kate, who is four years older than me.

Then about twenty years ago my dad wrote a book about Russian twentieth century history. Exciting stuff indeed but it became something of a leader on books about Russian twent...you get the idea. The result was that dad made pots of money, retired from teaching, bought a nice house and became a history professor, turning up on radio and television programs, his views being sought on many historical topics.

Dad has now become something of a mad professor. Poorly sighted and eccentric. He reminds me of the dotty professor in 'Back to the Future'!

Another consequence of his newly gained status was that he and mum decided to have more children. So at the age of fourteen I gained a baby sister, Beth, and four years later a baby brother, Robbie.

And now at the age of thirty two I found myself teaching them both history at school, something which pleased them far less than it did me.

Beth was taking some big end of year exams that summer and dad had asked me to help her with her revision. Not just with history but with various other subjects. The only one I couldn't help her with was science as I know nothing about that. I wouldn't say that Beth or I were particularly keen on dad's idea but after a couple of weeks it was going better than I expected.

Beth was proving to be a good student, far better than she normally was in my history classes, where she seemed bored at all times. She was actually quite clever. Beth was about five feet five tall, quite slim with short light brown hair. She was quite pretty, not that that was any concern to me. She had been dating a guy called Kevin for about a year, although I had only met him two or three times.

I would go to my parents house one day at the weekend and maybe one or two evenings a week and help her with her revision. Sophie moaned a bit about the extra time I was spending at my parents house but she understood it would only last a month or so and was for a good reason. We tried to work out a compromise where I would go over when Sophie was working late or if at the weekend when she was working.

++++++++++++++++++++++++++++++++++++++++++++

THE DEN

The story really begins on a hot Saturday afternoon in early June. Sophie is at home doing some catching up on a case she is working on. I have gone over to my parents house to help Beth with her revision. We normally do this in the 'den'. This is a room in the basement of our house. Since Kate and I were teenagers this has been a room to hang out in. Study, watch tv, read or just chill out. Whatever. The only thing - adults by invitation only!

Beth is wearing a pair of black shorts and a light blue bikini top. I'm in a t shirt and a pair of baggy shorts. Beth's choice of clothing is nothing new. We enjoy hot summers and to walk around in as little clothing as possible is the norm for everyone in these parts.

Also as a school teacher the teenage body is of no interest to me. In training one of the rules you soon learn is that the pupils must be regarded as children, no matter their level of physical or emotional development. Beth is my kid sister and a school pupil, nothing else. So I hardly noticed her body. In fact at that point if you had told me she had breasts I would have provably asked you when they appeared!

After a couple of hours of struggling through a geography text book we joined our parents and Robbie for dinner.

''Do you have to go straight home after dinner?'' mum asked me.

''No, no hurry. Sophie said to take my time. We'll have a day together tomorrow,'' I replied.

''It's a beautiful evening. Why don't you go for a drive up to the mountains?'' suggested dad.

I had recently bought a convertible BMW car which was proving a hit with friends and family alike.

''Oh can we?!'' Beth called out, excitedly.

''Ok. Who's coming?'' I asked.

''No I'm ok. I'm going over to Ben's,'' said Robbie. Ben was his best friend and also one of my students.

Mum and dad also declined. It was typical of dad to suggest something then not join in. As I said he can be a bit odd!

''Just you and me then kiddo,'' I smiled at Beth.

We finished dinner then went out to the car. I drove around for a while on the mountain roads before seeing a sign for Eagle Falls, a local beauty spot. Waterfalls, woodland and streams, it was a very popular place for walking and picnics. We used to go there a lot when we were younger, but I hadn't been in years.

I drove into the car park but I saw that the gate was locked.

''Oh it closes at six PM. That's a shame. What shall we do now?'' I wondered.

''I know, go towards that tree over there. There's a track you can drive down,'' suggested Beth.

''What over there?''

''Yeah, try it.''

I followed her instructions and we drove down a narrow dirt track for about ten minutes. Suddenly she slapped me on the shoulder.

''That's it! Stop here.''

She pointed towards a clump of bushes in front of a wooden fence.

''Where are we going?'' I asked.

''I know. Trust me. I came here with some friends last summer.''

We got out the car and she led the way through the bushes.

''Yes it's still here!'' she shouted.

I followed her through a hole in the fence and was rewarded by the view of a small lake surrounded by rocks and trees.

''This is it. We came here last year. Went swimming. No one ever comes this far down the trail, even when the park's busy,'' she explained.

The evening sun shone on the lake, creating a totally idyllic scene. We stood in silence for a couple of minutes, admiring the view and the peace.

''Beth this is beautiful.''

''Swim?'' she suggested.

''Err we don't have costumes.''

''No matter.''

She stepped towards the water's edge. With her back to me she unhooked her bikini top and then slipped out of her shorts and panties. I had hardly acknowledged the fact that she was naked when she dived into the water. She screamed in joy and swam around the small lake.

''You not coming in?''

''Like I said I don't have a costume.''

''Mark! Don't be so boring. Come in it's lovely.''

''Err...''

''You'll regret it.''

I have to admit I was tempted. I turned away from the lake and pulled off my shirt. Then I pulled off my shorts. I don't tend to wear underwear in hot weather. I still had my back to the lake and more importantly to my little sister. I glanced over my shoulder and when I was sure she wasn't looking I hurriedly jumped in.

It was lovely. So refreshing after such a hot day. We splashed and swam around, the water shielding our nudity. After about half an hour Beth said she was getting tired and was getting out.

Trying to be both a gentleman and a responsible big brother I tried to avert my gaze as she climbed out, although I did catch a glimpse of her bare ass as she clambered onto the rocks. However she made no real attempt to cover herself on dry land as she simply turned around and sat down, giving me a first side of her naked breasts and pussy.

Again I tried not to look, but noted a very small triangle of pubic hair and a small but pert pair of breasts.

'Stop looking!' I thought to myself.

Then it was my turn. I swam to the edge. I was going to ask her to turn away while I climbed out but decided that would only make her look even more and draw attention to my body so I decided to act as if this was all completely normal. Maybe she won't even look if I don't say anything, I thought.

So I heaved myself out of the water, onto a rock and quickly walked toward my pile of clothes, all the time aware of my cock swinging between my legs as I walked. Also, although I avoided eye contact I sensed Beth staring at me. I walked past her to my clothes and sat down. She was still naked, drying herself in the sun before dressing and I realized that was sensible.

My biggest fear is the fear of every man in such situations - an unwanted and unwelcome erection. I avoided looking at her bare back and tried not to think about erections. Fortunately nature itself saved me. An adult fox and four cubs appeared across the lake.

''Mark look! Foxes! Keep quiet.''

We watched them playing and washing in the evening sun for about fifteen minutes, completely forgetting about our state of undress. Only once they had gone did we dress ourselves, me with my back to my sister.

Once we had crawled back through the hole in the fence we started speaking.

''Wow! That was so cool! I can't believe we did that,'' exclaimed Beth.

''Lovely. Really refreshing,'' I replied, trying to sound calm.

''That was amazing! I loved it!''

''We shouldn't tell anybody. Our secret,'' I suggested.

''Huh? Oh sure, no problem.''

We got back into the car and drove back to our parents, telling them about the drive and the foxes, but leaving out the swimming part!

+++++++++++++++++++++++++++++++++++++++++++

Following my nude swim with my little sister, my mind was all over the place. Over the next week I tried not to think about it, but at odd moments the vision of her naked body would appear in my mind. I had only seen glimpses of her breasts and her pussy, seeing her ass more, but I found it difficult not to think about her. This was particularly difficult on the Wednesday morning when I taught her class. Every time I saw her I imagined her naked body, glimmering in the sun and the cool water of the lake.

I didn't see her for extra revision during the week. Sophie was going to a work conference at the weekend so we agreed that we would spend our weekday evenings together and I would spend as much time as necessary with Beth at the weekend.

So the following Saturday followed much the same pattern as the previous one. I drove to my parents house just after lunch. After chatting to my parents I asked after my brother and sister.

''Robbie is at Ben's house. Beth is down in the den, waiting for you,'' explained mum.

''Be gentle with her!'' joked dad.

I went downstairs. Beth was sitting at the table in the middle of the room. She was wearing a thin white top and a dark gray skirt. I felt relieved at her appearance as I thought that if she had been in a bikini top as usual I might have had problems concentrating!

In fact for the next two and a half hours we were able to do loads of revising and by the end I felt that everything had returned to normal. It seemed Beth had never had any problems with our nudity at the lake the previous week and I seemed to be the one who found it uncomfortable. Perhaps that's what comes with age and responsibly. To Beth it had just been a bit of fun, quite normal. Maybe her mind was still so innocent that nudity was not an issue?

We worked together, revising, and we chatted about her exams and how she felt her revision was progressing. We joked about some of dad's mad moments and she told me something funny Robbie had done during the week. In other words my relationship with my sister was the same as always. Thank god!

At one point I had looked at her shirt and clearly been able to see she was wearing a bra. The shirt was of a very thin material and quite see through. The sight of a bra and her generally more modest style of attire did make me wonder if she had deliberately tried to send a message to me - last week was a one off. I felt relieved about that.

After revising, we had dinner with our parents. Dad suggested another drive, like the previous week.

''Are you coming dad?'' I asked.

''I won't but I think your mother will.''

''Yes that would be lovely. What about you Beth?''

Beth nodded. I felt glad that mum was coming too.

''I'll just get changed,'' she said.

Mum and Beth disappeared to their bedrooms. I sat in the garden and chatted with dad. Mum had just appeared when the phone rang. She went off to answer it, just as Beth walked out into the garden.

''Ready?'' she asked.

At first glance she hadn't changed, except to put on a pair of shoes. I noticed after a moment or two that through her thin, see through shirt, something was different. She wasn't wearing a bra any longer. I could make out the shape of her nipples and the darker shade of her areolas. I tried not to stare. I wondered if dad noticed. Then mum appeared.

''That was my aunt. She wants me to pop round now and help her with something. Sorry.''

''Oh it's ok. Do you want a lift?'' I asked.

''No you two go for your drive. It'll do you good. It's only a twenty minute walk to her house.''

''Just you two again then,'' laughed dad.

''Don't you want to come then dad?'' I asked.

''No no. I've got a good book waiting to be read. Off you go now. Enjoy yourselves.''

We clambered into my car and drove off.

''Where to, kiddo?'' I smiled at Beth.

''Up to you. You're driving.''

We drove in the general direction of the mountains with Beth singing along to my cd.

''How about Eagle Falls again?'' she suddenly suggested, interrupting her own singing.

It had occurred to me, but I did not want to suggest it.

''Could do. But no swimming, ok?''

''Ok big brother. You're the boss.''

Of course I wasn't. We parked at the same spot, crawled behind the same bushes and through the same hole in the same fence. And we stood on the same rocks, looking across the same small lake.

And then Beth peeled off her top, revealing the lightly tanned skin of her bare back. She kicked off her shoes and pulled down her skirt. It seemed a bra wasn't the only piece of underwear she had removed before we came out. But what if mum hadn't had that phone call?

I watched as she jumped into the water. Again my own undressing was much more slow and cautious. Only when I was sure she wasn't looking did I turn around and hurriedly enter the water. A twenty minute swim followed before my sister climbed out, my eyes looking elsewhere, out of some strange brotherly respect.

When it was my turn to come out I swam to the edge.

''Could you look away for a moment or two please?''

''Why?''

''Because I don't want you seeing me...you know...naked.''

''Err Mark,'' she said pointing at her naked chest. I tried not to look.

''Yes but I always look away when you get in or out of the water.''

''Do you? Why?''

''Because you're my sister.''

''And your my brother. And that's exactly the reason I feel ok being like this around you.''

''Beth...please...''

''Ok.''

She looked away and I climbed out, walking past her and sitting a couple of feet behind her and to her left. No sooner had I sat down and she shuffled back to be nearer to me.

''That was fun again wasn't it?'' she said.

''Sure was. This is getting to be a bit of a habit for us,'' I laughed.

There were no foxes to distract me so I tried humor to keep my mind off the fact that I was sitting naked next to an equally naked teenage girl who happened to be my sister and a student in my class.

As any man knows, the more you try not to get an erection the more certain it is that you will get one. Obviously this always is in situations where an erection is particularly inappropriate.

So how obvious then that as I sat next to Beth my cock began to twitch. I tried not to think about it. Tried to think of anything but my current situation. Various thoughts of mundane things went through my head in the space of a few seconds. Custard, trees, driving a lorry, even early twentieth century Russian history, but inevitably I found myself with a full blown erection. My cock continued twitching even at full mast.

I raised my leg slightly in an attempt to shield it from my sister. I turned my whole body away from her. I tried to point out things in the distance in the forlorn hope that my erection would disappear as quickly as it appeared. Where are those damn foxes when you need them? Hmmm look at those fascinating cloud shapes up there.

Nothing worked.

''Mark you seem to have a bit of an erection there,'' Beth pointed out rather helpfully.

''Yes, errr, sorry, couldn't help it.''

''Ok.''

She said nothing more for a couple of rather uncomfortable minutes.

''I guess that's something us girls can be thankful for.''

''Huh?''

''We don't get massive great erections when we're turned on.''

''Oh right.''

''I mean our nipples get hard but I guess that's not the same as having one of those,'' she smiled, pointing at my cock.

''Beth, you're not helping. I'm trying to get it to go down.''

''Sorry.''

''It's ok. I forgive you.''

Minutes passed.

''Can I touch it?''

''Beth!''

''Well can I?''

''There must be a million reasons why you shouldn't.''

''I didn't ask if I should. I asked if I could,'' she responded with a wisdom way beyond her years.

I said nothing. Hoping that if I ignored her she would change the subject.

That didn't happen. Perhaps she mistakenly assumed my silence was a signal that I gave her permission as she simply reached across and prodded my hard member.

''Beth!!''

She ignored me and proceeded to explore my penis with her right hand. She slid her finger along its length, the tip and around my balls. Then she used two fingers to do the same journey. Finally she wrapped her hand around the shaft and gripped tightly.

Why I didn't stop her I can't answer to this day. I was bigger, stronger and I could have easily brushed her aside, stood up got dressed and stormed back to the car. I could have but I didn't. Instead I sat there meekly as my younger sister began to stroke my cock.

Her strokes gained pace and rhythm and I soon realized that what began as her simply asking to touch my penis was going to end up with her masturbating me. I knew that would be wrong but at that moment my cock was winning the battle of wills with my brain. I was turned on and horny and I was to my eternal shame enjoying having my kid sister jack me off.

''Beth I'm going to cum soon,'' I breathed after another three or four minutes of her stroking.

''I should hope so too. That was the idea.''

''Ooooh oh god oh yes that's it,'' I was beginning to lose control.

Moments later my cock twitched and I knew the battle was lost. Never again would I ever have that same big brother right to moral superiority as her handjob resulted in jet after jet of my sperm shooting out over her hand, my stomach and my leg.

''Enjoy that?'' she purred.

''I think so, if If I don't think about it,'' I replied.

''I want you to touch my tits now,'' she said as if she was asking me to make her a cup of coffee.