I was really disappointed because I had been dying to jerk off and realizedI probably wouldn't have enough privacy. My frustration had been intensifie...past the usual hormone induced urges of a normal 15 year old guy by my sisterSara, who shared the back seat with me all day. She wore short cutoffs anda t-shirt with no bra to keep the big nipples of her sweet 17 year old tittiesfrom being very noticeably displayed, and casually, incidentally rubbed orpressed against my arm or thigh several times. Turn around, bend down and get a good grip on the shelf," I said as I opened my fly and took out my cock. Matty looked at it and licked her lips nervously."Change your mind?" No, no I'm not. It's just that I have never done anything like this before and it's happening so fast." That's the idea Matty, it has to be fast. We need to get it done before we get caught. It is your choice sweetie, but you need to hurry up and make it."She looked nervously at me, down at my cock, back up at my face and. “Put me in and I will,” I replied. Lexi slipped the head of my cock into her pussy, then re-positioned herself, sliding my tool all the way into her wetness. Our pelvic bones met. Slowly and rhythmically, Lexi worked her hips back and forth, as my cock filled her pussy. I could feel the walls of her vagina constricting, tightening, as she ground her hips back and forth. My inner thighs tightened and I knew I was not going to be able to hold back, the inevitable. I shot my load deep inside of. "I'm a virgin, Jerry," Cindy warned. Jerry started whispering something to my sister which I couldn't hear and then Cindy said, "I'm not protected. I don't want to get pregnant." I'll be careful," said Jerry. I heard Cindy gasp and I figured my little sister was no longer a virgin. I couldn't stand it any longer. I wanted to see what was going on. I peered into the room as cautiously as I could. I couldn't believe what I saw. My 15-year-old sister was lying on her back on the bed. Her top and.