Wrong!

Beth came out with dad's beer. She put it on the table and sat down next to dad and opposite me.

''Dad was just admiring your outfit Beth,'' I winked at her.

''Pffff... admiring it? It's ridiculous,'' he grumbled.

''Thanks dad.''

''You don't wear it in public do you?'' he asked.

''No it's just for you boys. Don't tell mum will you?''

''I never tell your mother anything dear.''

''Thanks dad,'' she smiled, leaning across to kiss him on the cheek.

We sat in silence, drinking.

''Movie time in a moment,'' said Beth eventually.

''Are you coming Mark?'' she asked me.

''I hope so,'' I winked at her again.

''Men.''

''You don't mind if I watch a movie with Beth do you dad? I mean if you want company.''

''Good god no. I bought a book a few weeks ago. I've been trying to find some quiet time ever since to start it. Your mother is always finding jobs for me.''

Bet pushed her chair back and took another swig of beer. Out of dad's line of vision she calmly took her bikini top off. I stared at her. She stood up, still behind dad.

''Come down in five minutes Mark. I'll get myself...sorry the movie...ready.''

As she said that she pulled down her thong and was standing behind dad completely naked. She turned and walked towards the house as I desperately tried to distract dad by asking about a plant growing nearby.

Shortly after I went down to the den. The room was in darkness with only the light from the tv providing any illumination. Beth was lying naked on the couch. I pulled off my shorts and lay behind her, running my hands all over her body as she rubbed her ass against my cock.

After about ten minutes we heard dad coming down the stairs. The tv was on a very low volume so we could hear anyone approaching. Dad pushed open the door and looked in.

''Do either of you want a beer before I sit down with my book?''

We both did and dad went back upstairs. He obviously hadn't noticed our nudity in the dark. His vision was poor anyway so we guessed he wouldn't. When he returned a couple of minutes later we were still in the same position. He put our beers on a shelf by the door and left.

We waited a few minutes to see if he would come down again. No sound.

''Wait there. I'm just going to check on dad,'' said Beth.

She stood up and left the room, still naked. I heard her creeping up the stairs and on the hallway before creeping back down again.

''He's in his armchair, miles away now,'' she smiled.

''You're mad.''

''I've done that before. When it's just me and dad. His eyesight is so poor I know I can get away with it.''

''What you creep around naked?''

''Yep. It kind of turns me on. On Thursday evenings when mum and Robbie are out. I strip off and creep from room to room. I sort of follow dad but he doesn't know I'm there. I like that kind of thrill.''

''Mad.''

As she told me this I was sucking her nipples. I slid down and buried my face between her legs. I looked up at her and began to lick her juicy wet cunt.

''Oh god oh god. No one's ever done that to me. Kevin won't.''

I ignored her, continuing to fuck her with my tongue.

''Oh fuck oh fuck shit shit you cunt oh I love it!!''

''Shhhh...'' I briefly stopped licking her to tell her to be quiet.

''FUCK FUCK GONNA CUM FUCK YOU CUNT STOP OH GOD DON'T STOP!''

''Dad will hear,'' I scolded her again before resuming.

''SHIT YOU FUCKER OH SHIT OH FUCK OHHH OH GOD HELP ME I CAN'T OHHH!!''

Her orgasm struck, at least once. I continued to pleasure her with my mouth even when she had cum.

''OH OH OH OH OH GOD FUCK YOU CUNT YOU OH MY GOD YOU OH GOD JESUS FUCK SHIT OH YES OH YES OH YES!!''

Finally I guessed she had had enough. I leaned back and looked at her.

''That's for all your teasing little girl! Don't mess with big boys!''

''You bastard that was so good. Oh god I love you! I love that,'' she moaned.

Dad called out from the top of the stairs.

''Beth are you ok? Only I thought I heard you shouting,'' he asked.

''Oh sorry. Yes fine daddy. It was the movie not me.''

Dad went away, leaving Beth to recover. We lay together. I was still horny but I think I had worn her out for now. After half an hour or so of lying together I realized she was asleep. I quietly climbed out from behind her, put on my shorts and went upstairs, leaving her sleeping in the nude.

I went into the kitchen and put the kettle on to make a coffee. I checked on dad who was asleep in his armchair in the living room, before I returned to the kitchen. Just then the front door opened and in walked Robbie.

''Mark! I thought I saw your car in the driveway,'' he said.

''Yes Sophie is out for the night. I thought I'd come over here and see dad.''

Almost the truth.

''Cool. Where's dad?''

''Asleep in there.''

''Beth not in?''

''She's in the den.''

His eyes diverted immediately towards the stairs leading to the den when I remembered I'd left the door wide open when I'd come up.

''Hey Beth,'' he called, turning towards the stairway.

''Robbie don't! She's asleep. She's not feeling well,'' I said, stepping towards him and ushering him into the kitchen.

''Ok I'll go get changed then.''

The minute he had headed upstairs I rushed down to the den and woke Beth.

''Robbie's home. Get dressed.''

She finally woke and I heard our brother coming down from his room. I rushed back to the kitchen to finish making my coffee, and stood there chatting with him.

''I thought you were staying at Ben's.''

''I was going to but his mum was unwell so I thought I'd better come home.''

At that moment Beth appeared in the kitchen, wearing her sexy skimpy bikini. I realized that was the only thing she had to wear downstairs. I looked at her then at Robbie then saw his eyes nearly jumping out of their sockets.

''Hey squid. Thought you were out for the night,'' she whispered to him.

He explained to her. We followed her as she walked out into the garden, both of us staring at her ass then looking guiltily at each other.

We sat down for a while before Beth announced she was going to bed.

''Goodnight,'' she said, leaning over me to kiss me.

''Goodnight,'' she did the same to Robbie, before we both watched her disappear into the house.

I finished my coffee before heading home. Once I got home I couldn't stop thinking about the previous few hours. I went to bed but couldn't sleep, still awake my drunken wife Sophie came in at two thirty. The next morning I was first up and was joined by Sophie at about eleven AM. We sat at the garden table and she told me about evening.

''What did you do?'' she asked me after describing her night out.

''Oh not much. Popped round to see dad, and he lent me a book.''

''More revision with Beth then?''

''No I don't think she was in. I only saw dad. Wasn't there long,'' I lied.

After lunch Sophie and I sunbathed. One thing I should mention is that our garden is very secluded and in good weather we simply sunbathe in the nude. In fact on days when we are not expecting anyone, and get to spend the day together - rare - we can easily spend the whole day naked. This naturally involves us having sex, at least once. That Sunday was one of those days. We stripped off and lay down together and by the end of the day we had fucked four times, good even for us. Once we had gone to bed we lay together naked and I tried to persuade Sophie to make it five.

''Oh god Mark, haven't you had enough?'' she protested.

I finally persuaded her to give me a hand job so I wasn't entirely disappointed. As she stroked my cock she chatted to me.

''I don't know what it is but you seem particularly horny at the moment. I noticed that last week.''

''Sorry.''

''No don't be sorry. I'm just fascinated.''

''I don't know why. Maybe just the hot weather.''

''We get loads of hot weather.''

''Oh I don't know.''

''I'm not complaining.''

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

The next week was a strange one. My moods went a bit wild. I still thought of Beth a lot, but in quieter, more reflective moments I felt guilty or dirty or just plain stupid.

Stupid because as a teacher I was effectively involved with a student, breaking the golden rule.

Guilty because I was messing around behind my wife's back. Even though I had not yet had sex with Beth I could see it happening unless I took control of the situation sooner rather than later.

Dirty because Beth was my sister. My little sister, and this could ruin our relationship, our lives and those of the people we loved the most, our family.

At other times though I could be more positive and thought that I should just enjoy myself while the chance was there. You only live once and all that...

I sat out in my garden on the Tuesday evening, late into the night, with a beer in my hand. Sophie had gone to bed. I sat there (naked I might add!) and thought. I decided the best action to take was to step back and cool down a bit. If I could see Beth less frequently and we could clear our heads that might help. Certainly once the exams were over that would lessen our time together. Maybe Sophie and I could get away for a couple of weeks once the school vacation begins. Time away from Beth. My sister had a boyfriend, a seemingly steady one at that, yet she was still messing around with me. Definitely try not to see her, I decided.

The first thing was her lesson on Wednesday. I played it calm, avoiding contact with her. That's easy when you have twenty other seventeen and eighteen year old students there as well. I tried to avoid eye contact as well. Lesson over, that went well. Except that when all the other students had left I looked up from my desk and saw Beth standing in front of me.

''Hey,'' she said.

''Hey you.''

''I was just wondering when you're coming round next. My exams start next week.''

''Yes I know. Sorry. It's a bit crazy work-wise at the moment. Same reason, exams starting.''

''Oh.''

''To be honest Beth I kind of got the impression that you don't really need much help with your revision.''

''Huh?''

''Well you know we err we erm don't do much you know revising.''

She blushed. Oh shit she looked cute when she blushed.

''Yeah I know but... But it kinda helps.''

''What does?''

She began to stroke my hand with her fingers, acting really shy.

''Being with you. I sort of relax. Take my mind off things.''

''Beth you know...''

I was about to say something when my next class walked into the room. A bunch of noisy thirteen year olds.

''I'd better go. Pleeeeeeaase!!'' she said as she backed away from my desk.

And then she was gone. Well that went well. I don't think.

I sat at home that night still trying to make sense of it all.

Tell her it's got to stop? Now? At exam time? Wait a few weeks then stop it? Carry on and hope she'll lose interest? Carry on and let it run out of control? Sex?

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

On Thursday evening Sophie talked to me over dinner.

''You haven't been over to help Beth this week. Don't her exams start next week?'' she asked me.

''Yeah I know. Just a bit tired this week. She asked me the same thing after her lesson yesterday.''

''Still you should find the time. She's your sister.''

''I know. Truth is she is quite bright. She doesn't really need much help.''

''You know I was like that. Quite clever. But sometimes it runs deeper than that. I just needed someone next to me to boost my confidence. To tell me it would be alright. Maybe that's the case with her?''

''You could be right. I don't know. I just feel exhausted.''

She stood up and stood behind me, massaging my shoulders.

''My poor baby what's wrong. I was just saying the other night how you seemed to be sex mad and now you seem a bit down.''

''Maybe we can get a holiday when the school closes?''

While I was washing the dishes I could hear Sophie on the phone. After she came bouncing in.

''I just came off the phone to your mother. I've arranged for Beth to come here after school tomorrow and stay till Sunday afternoon. That way you can revise with her but also we can just chill with her, maybe go out. Perhaps the change of scene will do her good. Get her in the right place mentally for her exams.''

''Beth? Staying here?''

So after my last lesson on Friday I was marking some work, tidying up, when Beth appeared in my class room.

''Hey again,'' she smiled.

''Hey little one. Ready? Have you got all you need?''

''Yes, mum is coming over to your house about seven with my bag of clothes. I didn't want to bring it to school. Thanks for this.''

''Sophie's idea. Not mine. I don't know if it's a good one do you?''

''What's wrong?''

''Sorry, ignore me. Long week.''

Any thoughts that this would all go to plan disappeared when I realized that under Beth's white school blouse there was no bra.

''Let's go,'' I growled.

We drove home. I showed Beth the spare room. I was expecting mum to come at seven, and Sophie said she would be home by nine, so hopefully my sister and I wouldn't be at home alone for long. My tactic was to avoid us being alone together. But still at the back of my mind there was this temptation...

One rule was that I was certainly not to going to get into any situation where there was the slightest chance of being caught by my wife. Sophie is sharp, unlike my dad.

Beth came down from her room into the kitchen where I was preparing our dinner. She was still in her school uniform, as she would be until mum turned up.

We chatted for a while. I looked at the clock. Just after five thirty.

''When do you want to start revising?'' she asked me.

''That's up to you. We can do some later after dinner or leave it till tomorrow. We've got all weekend. Mostly.''

''Do some tonight and then on Sunday? Have a day off tomorrow?''

''That sounds good. You know you don't need much help. You'll be fine.''

''Thanks bro.''

She never called me bro.

We looked at each other for a moment. A moment longer than a moment normally is.

''Mark...?''

''Yeah?''

''Oh...nothing.''

''What?''

''No it's ok. I was going to ask you something but it'll pass.''

''Weirdo.''

''Freak.''

''Nerdy cow.''

''Fucker.''

''Bitch.''

We used to insult each other before. Before...before...well before.

I was laughing now, starting to feel the tension fall away.

''Mark. I do love you you know.''

''I love you too. You're my sister.''

''Is it right?''

''Is what right?''

''What we've been...?''

''Doing? You mean playing...''

''With each other. Touching...''

''Each other? Probably not but it's a lot better than keep finishing each others...''

''Sentences!'' she laughed.

We laughed and hugged each other. As brothers and sisters do. She stepped back and began to unbutton her school shirt.

''Beth...''

''I'm not wearing a bra you know.''

''I know.''

''How do you know?''

''I noticed when you were in my class room.''

''Do you often look at your students chests Mr Johnson?'' she joked, taking off her shirt.

''Only the female ones. To see if they're wearing bras.''

''Pervert,'' she said pulling down her skirt.

''I can see you're not wearing panties either.''

''Top marks. Anything else?'', she asked as she placed her right leg up onto the kitchen table.

''Errr...oh fuck...you've shaved your pussy?!''

''Well done. You have passed your exam.''

''What about an internal examination?'' I smiled, pulling off my clothes as quick as I could.

''That is the next grade,'' she said, sitting on the table and opening her legs as wide as she could.

I was now naked and I pushed the cooking utensils off the table on to the floor and pushed her back across the table. I climbed on to the table and above my sister.

''I want you so bad,'' I cried.

''Oh god me too. Please...please.''

I lowered myself towards her naked body and pushed my hard cock against her pussy lips. I looked deep into her eyes before I thrust myself into her. Deep into her.

''OH OH HMPH OH GOD'' she moaned as I pumped my cock into her.

''OH BETH!!''

''MARK MARK OH GOD YES YES!!''

We were fucking on my kitchen table. I couldn't believe it. Fucking my little sister. My own sister. How did this happen? Who cares?

''BETH OH GOD YES BETH!''

''OH OH OH FUCK FUCK YOU CUNT FUCK OH GOD!!''

She was not a quiet fuck. Not at all.

''OH FUCK OH GOD YES OH PLEASE OH OH OH FUCK FUCK FUCK SHIT MAKE ME CUM GONNA CUM''

''OH GOD BETH YOU'RE BEAUTIFUL YOU'RE THE BEST OH I WANT TO''

And I did. We both did.

My ejaculation was like an explosion. Deep in her cunt. She came several times. The house was quiet. The kitchen door was open. But our bodies were dripping in sweat and our shouting could have been heard for miles around it seemed. But I didn't care. Never had sex felt so special. So perverted. So dirty. We lay on that table, our chests heaving as our hearts thumped, and regained our breath and our strength.

I looked at the clock. Ten past six. Better tidy up...

Beth took her skirt and her shirt and headed upstairs for a shower. I dressed then tidied up, and tried to resume cooking. Mum arrived fifteen minutes late. Beth and I were sitting at the table in the garden eating when she arrived.

After we had finished eating I was clearing things away in the kitchen when I overheard mum talking to Beth.

''You're not wearing a bra, Beth.''

''No mum I know I'm not.''

''Why not?''

''The one I was wearing broke when I was at school. A wire broke and it was digging in to me. Really painful, so I had to throw it away before I left school.''

What a liar.

''You know you can see your breasts through that thin shirt?''

''Thanks mum. I'm sure no one did.''

Mum had just left when Sophie arrived home, then shortly after that I received a phone call from my friend, Dave, inviting me to play golf the next day. I checked with my wife.

''Well I was thinking of going into town shopping with Beth tomorrow so that's fine.''

On Saturday morning Dave came to pick me up before the girls were awake. When I came home about three in the afternoon they were both in the garden, in bikinis, new bikinis I think. Fairly skimpy bikinis. Sophie was on a lounger reading a book, while Beth was at the table, studying.

''Dave, this is my sister, Beth. Beth this is Dave.''

''Pleased to meet you Beth. You're his younger sister right?''

''Yes we've got an older sister too. And a little brother.''

''And what do you do? For a job?''

''Oh I'm still at school.''

''Not his school?''

''Unfortunately yes. He's my history teacher. He's the worst teacher in the school!''

''Ha ha! I can imagine. Hi Sophie.''

He went over to my wife and kissed her on the cheek, before heading home. I went upstairs to shower and change. When I came down Sophie was topless. I gave her a curious look.

''Well I knew you'd bring Dave in. I had to wait till he'd gone!''

''I'm going to clean the car.''

''Little boys and their toys. Don't make too much mess making love to it!'' teased my wife.

When I had finished washing the car I came back in and through to the garden. To my amazement and not small amount of terror Beth was lying on the lounger next to Sophie's, also topless. I stopped for a second to gather my thoughts then carried on, pretending not to see.

''Shall we go out tonight? For dinner?'' I suggested.

We agreed on a pizza, then we all changed into more suitable clothes, the girls in particular. After we got home we sat and shared a bottle of wine before heading to bed.

As I lay in bed, sucking my wife's erect nipples she started talking.

''I can't believe your sister was topless today.''

''Was she? When?'' I lied.

''When you were washing the car.''

''Do you know I never even noticed.''