In Your Sister An Erotic Story "ALL the way up in your little sister," Momma insisted. Momma had caught the two of us "making out." We weren't really fucking or anything like that, just feeling each other up, and kissing, and stuff like that. Momma caught us. Boy was she mad! After yelling and screaming, calling Lori a slut, and me even more unmentionable names, Momma finally calmed down. Or at least, she seemed to. What she did next, I still find hard to believe. At first, I figured that Momma had cracked. You know, gone over the edge. Loony-bin. That stuff. Well, I guess Momma cracked all right. Cracked right out of her shell. Inside, Momma is a very kinky lady, and I guess she had been holding it back for years. Anyway, once she realized what we were doing, Momma decided (probably correctly) that no matter how much she screamed and hollered, we probably wouldn't stop sneaking around and playing with each other. So, she decided that if we were going to play around, we might as well do it right. In fact, that's what she told us. "Huh?" I said. Lori's mouth was gaping too. "I said, if you're going to fuck around with your little sister, you might as well REALLY fuck her, and do it right." I still couldn't believe what I was hearing. My staid, prim, old-fashioned mother, actually TELLING me to fuck my own sister? No way! Momma had just started, however. "You're not on the pill, are you?" she asked Lori. "Momma!" You could tell by the tone, that my little sister had never even thought of such a thing. I mean, you don't go on the pill, unless you PLAN on being fucked. Lori was still a virgin. Momma semi-apologized, "Well, you never know. Some kids get them from school, or the free-clinic. They aren't allowed to notify parents any more, unless the kids tell them to." Momma looked at Lori even closer. "How long ago was your last period?" she asked. Lori thought a bit, then responded, "I dunno, about two or three weeks ago. Somewhere in there." "Good," said Momma. "Now why don't you two get undressed, and do this properly." "Steve," she said, turning to me, "if you're going to fuck your little sister, you'll both be more comfortable on the bed." Momma WANTED me to fuck my sister? I looked at Momma in astonishment. Momma's face clouded up again. "NOW!" she said, making us both jump. "I'd better see nothing but two naked bodies in your bedroom Lori," she said emphatically, "in two minutes, or you're both going to be sorry!" If there's one thing about Momma (Or Daddy, for that matter.) she doesn't threaten lightly. Lori and I were moving before Momma finished her threat, shedding clothes as we went. By the time Momma made her slower way into my little sister's bedroom, we were both naked as jaybirds, and sitting on the bed waiting. Momma STILL looked annoyed. "Well, what are you two waiting for?" she asked. "I told you Steve, fuck your sister. What's the matter, do I have to put it in for you?" she asked sarcastically. "But Momma," wailed Lori, "we don't have any condoms! That's why we were just feeling around." Momma looked as if she were going to blow her top. "Not in MY house, you don't," she exploded. "As I said before, if you're gong to fuck, you're going to do it right. Now get started, or get out!" Momma looked as if she meant it. Well, at 15, I sure wasn't ready to leave home, and if I wasn't, my little 10 year old sister wasn't either. We looked at each other and shrugged. Well, if that was what Momma wanted, that's what she would get. If my little sister had a baby, well Momma asked for it. Somehow I knew that Momma would be overjoyed, if Lori showed up with a big belly. Lori lay on her back; and I put my cock inside her. Yeah, just like that. No foreplay, no sucking cock, no twiddling her twat. Just up and stick it in. After all, that was what Momma wanted, wasn't it? Besides, we had gotten hot and slippery enough, before Momma caught us. That, and the thought of actually fucking my little sister, and getting her pregnant, with Momma's permission yet, was unbelievably exciting. (Permission? Hell, Momma was almost INSISTING that I knock the kid up.) As I said, I did it. I pushed my big cock up inside my little sister's tight little hole, and gave her a belly full of baby-juice. Lori only let out a little squeak, when I slid through her hymen, then she was grunting and moaning as though she had been fucking for years. As I mentioned before, I did it. The feel of the little girl's tight little slit squeezing and clamping on my already pre-cum leaking prick was too much. After all, I hadn't really been inside a girl before, let alone one as tight and horny as Lori. I made about two big strokes, in about 10 seconds, and I lost it. I pushed my cock up inside my little sister, and gave her what she wanted: a bellyful of her own big brother's incestuous sperm. That's when Momma said those words at the beginning of this story. "ALL the way up in your little sister," Momma insisted. I grunted, and did my best. Pushing up as hard as I could, I did my best to plant as much of my baby-making seed as far up in the little girl's tight little belly as it would go. Momma seemed to be satisfied. Once she had seen me do my best to impregnate my 10-year-old little sister, she calmed down a lot. Momma made it clear to both of us, that we could play around with each other all we wanted, we could even use birth-control, when she wasn't around, but not the pill. She just insisted that if we WERE going to play around, that at least once a month, we stopped "playing," and did it right. Yeah, just what you think. From then on, Momma practically ignored the two of us, and our almost constant sex-show. That is, unless we made it TOO obvious, or invited her in to watch. Once a month though, Momma insisted on watching the two of us fuck. She always made sure that Lori was in the middle of her period, and that we didn't use any protection at all during that one time. After the first time, Momma always insisted that my little sister go to bed without washing up afterwards, so that her big brother's sperm would have a chance to soak in. Then, for a month, she would leave us alone. Don't get me wrong, Momma didn't INSIST that I impregnate my little sister. She just insisted that if the two of us were going to fool around, then at least once a month, we had to take our chances that I MIGHT make a baby in my little sister. There's no way, that Lori and I were going to stop fucking, once we started. Also, as you might guess, and Momma probably planned; we figured that if we were taking a chance part of the time, what difference did it make, the rest of the time. Except for a few days at the beginning, we didn't use any birth-control when Momma WASN'T watching either. After a while, it got to be quite a kick, thinking I was planting a baby in my cute little sister's flat little tummy. It took longer than you might think. Lori had just passed her 13th birthday, when she finally missed her first period. By the time she was 14 though, we were already working on a little sister for our son to fuck. Well, as Momma said, "If you're going to do it, you might as well do it right."