I found a Cave

I 24 live on the family farm with my parents and sister 21, other close family own farms in the area. We've some hills as part boundary of our farm; steep sides face our farm the rest outside the farm is covered with forest. Every now and then especially after heavy rain the cliff have a rock side. Over the years we collected some rocks projects around the farm. Retaining walls here and there and filling in washouts on our dirt roads. So, after heavy rain I would investigate to see if there were move useful rocks. Then on one inspection I saw a split in the cliff face, I thought I could get thru to see what was inside. I could and there was a cave about ten feet across and going back about twenty feet the roof was about twelve feet close to entrance but reduced in height the further it went back. On the farm there wasn't much privacy, wherever you went as the farm was mostly flat and the house and farm building were on the only rise till you got to the cliff boundary. A group of trees were near there also only ones on the farm except the house garden. I decided to keep the cave my personal secret; it would be my private place. I did go on dates but hadn't had any success, likewise my sister. The available people to date were limited, as some our ages went off to college and other were close relatives. Also getting into town was a problem in rainy weather, as the road went under quickly. Anyway, after a couple weeks, I'd set up the cave to suit me battery lanterns and made a sofa frame out of old pallets covered by foam cushions it was quite comfortable. I'd started to disappear and that took my sister's interest, so one afternoon she came looking. She had seen me head towards the cliff and came to see what I was doing. It took her several minutes to find the cave as she came from the left side of the cave which was slightly hidden from that direction. But once in front or looking from the right side it was easier to spot. She entered the cave without saying anything, catching me masturbating. Highly amused at first, but then her looking at my hard cock caused her arousal. She asked could she touch it; I just nodded. After touching my cock, she started to finish my masturbation herself. I touched her breasts and she didn't say anything, so I started fondling them. Then I came getting me cum on her arm and top. That seemed to end the moment, but my sister offered to do it again another time. But it was getting late and so we headed back to the house. I was busy for the next serval days and so didn't go to the cave. Then I had to go to town to get some chicken feed and a few things from the supermarket for mother. I knew from reading my magazines that more girls would suck your cock if you had condoms than without any. I hoped I might talk my sister into doing it for me, mainly because she had masturbated me before. Finally, I'd a break and headed for the cave. Didn't my sister I was going as she was busy helping our mother. But she saw me leave, she soon wasn't needed anymore and headed for the cave herself. She arrived as I'd just finished setting myself up to start reading and masturbating. With sister's arrival my interest in the magazine dropped off. My sister and I talked, she looked the magazine and offered to masturbate me again. I accepted and asked would she remove her top and bra, she just removed them no hesitation. I decided to ask her about giving me a blowjob, telling her I'd condoms. At first, she stayed silent and she would. I really enjoyed that afternoon in the cave. It was how it was for the next two weeks, but I slowly was able to finger her and even lick her pussy. Which of course lead to us actually fucking, once we started fucking it became new routine at the cave. Had to buy more condoms, but my sister was with me and instead of the normal condoms she chooses favored one. That's our sex life now, we do date if we can find someone to date, but we're together for the only sex we get.