Playing with My Little Sis (Fictionalized Story)

My parents were getting the house remodeled, and right then they were working on my sister's bedroom. That meant that she was sleeping with me for the first time since we were little kids. She of course was excited to spend more time with her big brother, but I wasn't looking forward to the hoard of stuffed animals that were about to invade my bed. Soon, however, I would change my mind about the new sleeping arrangements. First, I should probably mention that my family were nudists. I never had clothes on around the house, and my sister, who I will refer to as Maddie, usually just wore underwear without a top. Because of this, we were completely comfortable with our bodies, and didn't spend too much time thinking about the other's anatomy. That all changed one night. It was late, and we were whispering to each other about something instead of sleeping. As our conversation went on, I gradually noticed that Maddie would occasionally glance down when she was talking. It was just for a split second, but it was definitely happening. "What do you keep looking at?" I asked her. She blushed, as if I had caught her doing something she shouldn't be. She seemed to debate for a second whether or not to tell me the truth. Her honesty must have won out, because she whispered that she had been looking at my penis. For some reason, my heart fluttered when she said this. We saw each other's privates all the time, so why was she so interested all of a sudden? The only way to find out was to ask, so I did. "It's just that, it looks so small right now, but I could've sworn I've seen it bigger," she replied. Now, at this time in my life, I didn't know anything about sex, so I didn't think there was anything wrong with showing her what I had learned about that. "Yeah, it does get bigger sometimes. I don't know why it does it, but I know one way to make it happen. Wanna see?" Needing to satisfy her curiosity, she simply nodded at me. So, I showed her how my penis would get bigger if I played with it. At the time, I didn't know the "proper" technique to masturbate, had never done it to orgasm, and didn't even know what I was doing was called masturbation. Instead of taking my cock in my fist, I simply used my index finger to twirl it around. As promised, it began to grow in size. My sister had to stifle a giggle to make sure we didn't accidentally wake up our parents. "That's so cool!" Maddie said. "Can I try it?" "Sure! Just wait for it to get small again." We lay in silence while waiting. I knew it would shrink faster if I thought of something else (though I didn't know why), but I'm sure Maddie never took her eyes off it as it returned to normal size. "I'm ready," I told my sister after a while. She started exactly like I had showed her, by twirling my cock around with her finger. Wow! It felt so different when someone else was doing it. It was like she had sent an electric shock through my body. Maddie giggled again, louder this time. "It's making me all warm inside my tummy!" she said. Apparently, I wasn't the only one who was feeling something strange. As my cock got bigger and straighter, it became harder to use my twirling method. This was usually where I stopped, but Maddie decided to do something different and grasped it with her whole hand. As she adjusted herself into a sitting position, her hand quickly bobbed up and down along my shaft. Another shock went through my body, and I moaned lightly. My sister mistook my pleasure for pain, and she removed her hand and started apologizing. "No, don't stop!" I told her. "It feels good down there, almost like you're tickling me." She returned her hand, and I instructed her to go up and down again. My whole body was on fire, and I could tell Maddie was enjoying herself too. I was disappointed when she stopped again. "I feel funny, and my privates are tingling," she told me as she removed her underwear. "Do you think if you touched me down there I would feel as good as you do?" "I guess we could try," I said. At that point, I would've done anything she said, so long as she kept playing with me. I sat up to face her, and as she resumed stroking me, I began playing with her. I had obviously never done anything like this before, and I had no clue what I was doing. I noticed that she was wet, but just assumed that she, like me, was sweating. I kind of just rubbed up and down her slit, hoping that she could feel something like I was. The pleasure was so intense by this point that I'm surprised I was able to do anything at all. I probably would have had my first orgasm by then, but Maddie was as clueless as I was and was still stroking at a snail's pace. The stars must've aligned just right that night, because I stumbled upon Maddie's clit and heard her gasp. "Yes! Right there! Keep rubbing there, that felt so good!" she exclaimed. Now that she was being taken care of as well, Maddie's breath was on pace with mine, and her hand was moving much faster. My heart was racing, and my whole body was light. I felt a pressure building up that I recognized meant I needed to pee. I thought about asking her to stop, but it just felt so amazing, so I decided that I could hold it. Then I heard Maddie moan, and it was enough to launch my first orgasm. I stopped rubbing her as my whole body stiffened up. Then, my cock started throbbing, out of my control. Waves of pleasure crashed down on my whole body, and something shot out of my cock. It was clear, not quite cum yet, but it was definitely not pee. My sister, however, failed to make the distinction, and let go of me as she buried her face in her pillow to muffle her laughter. "You just peed yourself!" she said once she had recovered. "No, that was something else. It was amazing Maddie! Like the best thing I've ever felt, all over my body! Here, you need to feel it too," I said as I resumed circling her clit. As hard as she might try to be quiet, a cute little moan escaped her lips every few seconds. I was glad that I could make her feel so good! Soon, she was breathing even faster and was squirming around in excitement. Then, her whole body tensed up, and her face contorted into an expression of pure pleasure. I stopped touching her, and watched in amazement as her whole body spasmed. It looked like it was taking all her willpower not to scream out. Then it was over, and we both lay in silence, panting. "Wow," she said eventually. "Wow," I agreed. "We should sleep now, but can we do that again tomorrow?" my sister asked me. Of course we did, and just about every night after that too. We only stopped when she moved back into her room. We never talked about it again, but I still get off to thoughts of those nights, and I'm sure she does too. Sometimes, when the house is really quiet, I can still hear her moaning through the wall. God I love my sister.