My Sister and Her Friends Had the Most Incredible Request

My twin sister Junie, and her two friends came to my bedroom door all giggly, as usual. They had a request, and it couldn't have been stranger if they asked me to reverse the earth's poles. They unraveled their request slowly, all hesitant, shy, and goofy. At first I thought I understood, but when they got to the heart of the matter, I couldn't believe what I was hearing, and I was immediately embarrassed. It seems the three girls were teamed up in biology class to do a simple little project. They were to bring in something to examine under a microscope. I figured they wanted me to pull the wings off a bug or something. Cool, I could do that. But why all the giggles? "No," Junie said, seemingly almost frustrated by my lack of understanding. "Not a bug. We need some sperm." I couldn't even think of an answer, while I'm sure my face turned beet red. My first impulse was to slam the bedroom door on the three of them and yell 'Fuck off.' I mean, the whole notion was way too embarrassing. On the other hand, at 16, my hormones were always raging. I had not yet even seen a real live vagina. Well, maybe Junie when we were four or five years old, but that didn't count. I started to mull the possibilities over in my head. I came to realize it would be pretty cool. I could jerk off, hand them a little bottle of sperm, and they'd know I did it, and they'd have a sort of souvenir. On yet another hand, that would be admitting that I masturbated, something that just wasn't done among people our age back then. But what if? What if I did that for them? Wouldn't it be the coolest thing in the world to provide them a sperm sample? I started to cave in, the hormones in me were winning over my cautious intelligence. "OK," I said in a strange voice. I sounded a bit too high-pitched, and kind of shaky. Weird. I repeated in a stronger voice, "OK, sure, since you're my sister, and since you girls need it for school. Just don't tell anyone where it came from, alright?" Suddenly, I regretted saying that I would do it. I hadn't thought it through, but if they had sperm in their biology class, they'd pretty surely tell everyone where it came from. My face got redder thinking about everyone in the school knowing I jerked off, and by gosh, maybe they'd make mental pictures of me jerking off. How embarrassing! I could feel the heat in my cheeks. "I changed my mind," I said, somewhat more forcefully than I intended, trying to keep my voice from going high and shaky again. "Oh, come on. It's for science," Kathy cajoled. We went back and forth a bit, me and the three girls, but finally after they promised profusely that they wouldn't reveal the source, I did relent. Hormones again. I had an empty bottle from an old chemistry set in my room. I started to close the door telling them I'd fill the bottle and give it to them in a little while. "No, we need to watch," Junie stated. "Yeah, yeah," the other two girls chimed in. "Why?" "Because.... um, because we need to know that it's real sperm, not something fake you could put in the bottle." You'd think I'd object to that, but I immediately pictured, well, I don't know what exactly, something about the three girls all naked, and me naked, and maybe getting a handjob or a blowjob or something, especially from Kathy. Or the other girl, Nicole, for that matter. Nikky was a supe-hot looking girl with Korean parents. She didn't even realize how incredibly sexy she was with that super-long straight black hair of hers. My imagining was all quite nebulous, but it was strongly sexual notion. I could feel a stirring in my pants. I pretended to object, and be all sheepish, but I was all set for whatever might happen next. And yet, I didn't make any move. What should I do, just whip my pants off in front of these girls? That would be inelegant, to say the least. Maybe somehow tell them they had to get naked first? Sure, but how, exactly, would I justify that? I won't bore you with the details. Suffice it to say that I ended up totally naked in front of them, and none of the three girls removed a stitch. I think in retrospect, I didn't need to remove my T-shirt, but it seemed appropriate at the time, so I was, in fact, fully naked. My penis was immediately hard and I felt many things at once: I was feeling a sort of shame, like I was doing something wrong. I had to remind myself it was 'for science.' I felt sexually excited, of course. And, I felt proud. My dick had only recently come into its full size, and I had a nice nest of black hair around my balls with a slight trail leading up toward my belly button. And, I have to admit, my body, although perhaps a bit slim, was pretty athletic. "That's it?" Kathy asked. "I thought your penis would be bigger." That set me back for a second, but Junie stepped right up to the plate and said, "It seems huge to me." The world was right again:) "Come on, masturbate," Nicole commanded. I was surprised she even knew the word. So I did. I started to pull my foreskin up and down and all too soon, I was saying, "I'm gonna cum, I'm gunna cum." My sister grabbed the little bottle, and held it near the tip of my dick. I was out of control, and started spurting. She only got a couple of drops in the bottle. The rest landed on the floor. And it was much more cum than usual. It was probably the strongest orgasm of my life. My knees were so weak I had to sit down on the edge of my bed. The girls had been dead silent during the procedure. Kathy broke the silence saying, "That's it? I thought there'd be a lot more sperm than that." I decided right then that I didn't really like Kathy all that much, but mostly, I was in the combination of the afterglow of a super orgasm, and at the same time, I was becoming very, very shy. No, more than shy. Concerned that I shouldn't have done that. I shouldn't have been naked and jerked off in front of the girls. As soon as I could, I put on my pants, and politely shooed the the girls, with their little bottle, out of my room. It took me several days to recover. I jerked off several times reliving the experience. But I also had several bouts of absolute fear, like I burned down a house or something. I was sure the whole school would be talking about me. Nothing happened, and so after a week, it was entirely forgotten. Then, a knock at my bedroom door. I could tell it was the three of them again. I coudl hear them tittering. "What?" I asked as I opened the door. "The sample didn't work," Junie said. "By the time we got to school, it was kind of melted or something. We couldn't see any sperm in it. We need another sample. This time we'll refrigerate it." Sometimes I'm very proud of my quick mind. I answered, "Not unless you girls participate also."