It was a violent storm that caused my family's boat to sink somewhere in the South Pacific. My sister Annie and I were the only survivors and that was only because of dumb luck. We both found ourselves washed up on the white sands of a deserted island. I stood up brushed my self off and looked around for signs of civilization. Under a piece of the boat lay my little sister unconscious. I slid the piece off her and cradled her in my arms while we cried for our parents which we assumed to be dead. With a cough and a sputter of water Annie opened her eyes and saw me crying. She questioned me as to what the problem is and when I told her what happened we lay there and cried for a long time.
When I regained composure I stood and looked around. I had to guess that we were going to be there for a while so I looked for a water source. Annie called out for me and I told her I would be right back with some water for her. She sat and looked out at the water and I turned and headed off the beach to look for a stream. Through some heavy ferns and a boulder I came to a clearing where I saw the second most beautiful thing I had ever seen. A cascading waterfall from a ridge into a pool of crystal water probably ten feet deep. I found a large palm leaf and formed it into a cup shape. Leaning down I scooped into the water collecting some for Annie.
When I got back to the beach she quickly drank down the water and gave me a hug. "How long do you think we will be here?" She said burying her face into my now very filthy shirt. "I don't know sis. It could be a long time before they discover us... Until then we need to do our best to survive." And so the adventure began...
Approximately three months went by and the two of us were getting on just fine. It was my 18th birthday and Annie showed up at our improvised hut and gave me my gift. We had grown close over the three months and several times when we were sleeping next to each other I accidentally got erections when she brushed against me. Perhaps she knew my hormones were raging having never been with a woman. I was working on my fishing spear when she entered pushing the spear out of the way and sitting on my lap. With her legs dangling behind me.
She looked deeply into my eyes and then whispered into my ear, "Do you want you birthday present?" I could do nothing but nod as the sensation on my lap caused my dick to strain against my shorts. Her lips pressed against mine and I pulled her body close to me. I didn't care that I was making out with my sister on an abandoned island. To me she was the most beautiful girl I had ever known and I wanted her more than anything. Her hands roamed across my body and mine hers. I lifted the now worn out shirt from her body and slipped my hands across her now large supple breasts. Her areolas were protruding as I touched them.