I was thirteen when I discovered that rubbing my penis against the bedclothes gave me a nice sensation, which rapidly developed into my first climax. I am circumcised, so I couldn't masturbate as most guys do, by sliding their foreskin over their penis head ... I had to rub mine against something. Until now, my younger sister had been nothing but a pest to me, but suddenly I saw her in a new light. One night I crept into her room, and slid my hand under her bedclothes. I felt the elastic of her panties, and gently pulled it down, making sure I didn't wake her. Pushing the bedclothes aside, I could now just about see her little pussy, hairless and naked in the darkness. I slid into the bed beside her, and rubbed my cock against her. "what are you doing?" she woke. "it's alright,"I fumbled ... "one day this will be normal for you, one day you'll have a vagina ... You'll understand then..." With that, I came over her, then snuck out of her room. Amazingly, she didn't tell my parents. It was three years later that we were both watching late TV. Parents had gone to bed, and sis was in her nightie in the armchair closest to the fire. I had given up interest in what was on TV when I noticed she was masturbating, ever so gently. Was she? Yes, definitely, her finger was between her legs... Stroking herself slowly through the cloth of her nightie.... My cock was hard now, and I pulled it out of my pants, wondering if she'd notice out of the corner of her eye. If she did, she ignored it. Tentatively, I reached across to wher her hand was... I felt the movement of her finger on her clit, and added my finger to it. she didn't flich, so I reached down a drew her nightie up. Her pussy was different than the first time I'd played with it. Not just a crease now, but a bit more bulbous, and covered with a light layer of blonde fur.... I allowed her to guide my finger between those sweet lips, to stimulate her little clit... She drew a sharp breath as I hit the spot... I knew this had to go further, and now knelt before her naked pussy, my cock standing proud in front of me... She looked at it briefly, then took it in hand, and guided it to that cute clit. Then she rubbed me against her until eventually I could hold back no longer... My cum shot over her pussy and her tummy... She giggled, then went to bed! I never did get to fuck her properly, until two years later! (wait for part two!)