Sex Object

I'm Alvin 24 single lived with my mother and 2 sisters back in the 1970's, we lived on a small chicken farm. Twenty miles from town, our farm was 25 acres in a hollow between 2 hills. The hills and most of the land around is state forest or national park. We were the only people living in that area for 15 miles. My father died 6 years before of a heart attack, So it was just me, my mother Mary 48 sister Jean 26 single and sister Susan 21. We keep to ourselves, except when relations visit, which isn't all that often. When uncle Keith and family came a visit before moving to west coast, I had to share a bed Jean and Susan. I had done that before, but this time my cock got really hard after seeing Jean's tit while she was changing. I was against the wall on the bed and Jean was in the middle. I just couldn't stop thinking of her tit, during the night my cock poked out of my PJ's and touched her bottom. This woke her up and she rolled over to see what was poking her. On seeing it was my cock, she asked Why I was poking her with it. I said It wouldn't go down, Well put away or something she said. I've tried and it won't stay there I answered. I will put away for you she answered, so she tried to put it back in my PJ's. But it kept coming out again, so she then said She would get me off. She started to stroke it and after a bit she got me off. The next day I was in the barn working after uncle Keith and family had gone. When Jean came into the barn and walking straight over to me, she said Let me see that cock of yours. Why I asked, she replied Well I want to see what I pulled off last night. If you let me see it, I'll let you see mine. I agreed and dropped my trousers, It's not as big as last night she said. Then she lifted her dress and dropped her panties to show me hers pussy, my cock went hard straight away. Well look at that, your cock likes my pussy she said. I think we should get out of sight or we'll be in big trouble I said. Okay she answered, so we went behind a stack of straw bales. There she touched my cock again and said I could touch her pussy. We were there for a while and she got me to cum again. Next day she came to me again and we done the same things behind the bales. The next day we got a bit more adventurous and sucked my cock and I licked her pussy. I inserted my finger inside her and played with her tits. The next day we had full sex and I came on her belly, this became a regular thing for us. It was just over 2 weeks later that Susan caught us fucking and we convinced her to join in. I made a mistake with Susan and failed to pullout in time and she would get pregnant from it. The next day our mother Mary caught the three of us at it and was very cross at us. Later that day she asked how long had we been having sex together and what precautions had we taken. She wasn't very happy about the answer, but said that she got horny and knows how hard it can be to avoid temptation. She was also unhappy that I had cum inside Susan, but all she said That take more care when having sex. Later after I went to bed Mary came into my room and asked me for sex. From then on I slept in her bed and Jean and Susan would join us, Susan had got pregnant and so Jean wanted a baby to. I never again tried to avoid putting sperm in my sisters again . I never married and have always lived with my sisters as man and wife, having 7 children with them. The government purchased our farm in the 1980's and we moved to another farm in another state to keep raising chickens. As far as anyone knows we're married.