Human Reproduction Ch. 01

Mason let out a powerful grunt as the sensation of sliding the sensitive head of his cock into Megan nearly overwhelmed him. "I know what you mean. It's like instinct is completely overriding my free will. Even now I'm thinking 'maybe I'll just slide the tip in,' but ungh-" Unable to hold himself back any longer, Mason's hips bucked, and he found himself fully thrusting into Megan's inviting depths, where the sensations only magnified themselves and made him want to do it again.

Megan too was just as caught up in her sudden sensation of satisfying fullness, like she was doing exactly what she was supposed to, and in her excitement she began moving her torso up and down Mason's body once more, needing to feel that sensation again and again, regardless of what it was doing to Mason's dangerously sensitive dick in the meantime.

Mason could feel the sensations starting to build as Megan's movements sent his eager cock sliding into her tight hole over and over again. He knew all too well what was happening to him as her pussy continued to pull at him, but he couldn't stop his arousal from building toward the point where his body would react with spontaneous finality, and would begin filling his enticing feminine partner with his potent cum whether he wanted to or not.

Her body was acting out its role as well, milking his cock and pulling at his dwindling resistance, cajoling him to embrace the pleasurable sensations and voluntarily stimulate himself inside her up to the point where control would be taken away from him.

Mason knew it was coming, but it felt too good to pull out at this point, and so he didn't. His body wanted this too badly, and as the sensation washed over him and his dick began to involuntarily tighten, just as Dr. Jeff had said it would, there was nothing he could do to stop it. He instinctively gripped Megan's smooth torso in his arms and powerfully thrust his hips up into her one final time, holding her in place as his dick inevitably began to pump, dumping an overwhelming load of his genetic information into his fertile classmate. He knew that her sexy body had gotten exactly what it wanted out of him, but he was unable to feel anything other than dazed satisfaction at that knowledge as his hips continued to involuntarily buck, and his body rewarded him with pleasure for giving up his seed.

Megan was just as compelled by instinct to sit there and accept the catalyzing essence her body had caused his to expel, overwhelmed with pleasure at having fulfilled her own reproductive role of allowing herself to be inseminated. All the while, she reassured herself with the thought that it probably wouldn't take even as her body began combining his genetic material with her own. Even so, she knew there was nothing she could do to prevent her body's natural reaction to having her mate's potent cum inside of her, but she also knew her body had wanted her to get herself pregnant in the first place, so whatever happened wouldn't be her fault. Or Mason's, for that matter.

"Wow, our bodies really wanted us to mate today, huh?" Mason asked as he slowly withdrew his deflating cock from the cute girl's tight pussy. His head was swimming with primal contentment even as he reflected on how quickly his sexual desire for Megan had faded now that he had successfully impregnated her.

"I know! Dr. Jeff was totally right!" she said, feeling his potent cum ooze out of her fertile, eighteen year-old body as she rolled off of him and stood up, still a bit weak in the knees. *Oh man, my instincts and hormones have really done it to me this time. Oh well, there's not really anything I could have done to prevent it. I just couldn't help myself! My lizard brain made me notice how manly and sexy you looked, and I just felt so flirty all of a sudden, and the next thing I knew I was throwing myself at you! It's no wonder you wanted to mate with me - my body was tempting you sexually in every way it could think of!"

"Ugh, I know!" Joey muttered, a bit miffed at just how easily his own sexual instincts had manipulated his behavior. And now the deed was done. He could still feel his oversensitive dick tingling slightly with the lingering aftersensation of his fateful orgasm as he pulled his boxers up and tucked it back inside. "When I saw you approaching with that look on your face I already knew what had happened, that your body was trying to get you pregnant, but by then it was too late. I'd always thought you were cute, so when you came up and pressed yourself against me like that, I wanted you to do it, even knowing what it would do to me.

"I'd already noticed how sexy you looked today for some reason, and then your soft curves felt so good that my dick started throbbing with arousal. Once that happened it was like I could feel the cloud of testosterone flooding my brain, and then all I could think about was getting my cock into your tight pussy where you could make me cum! I knew what might happen if I did, but my body wanted you so badly, and once I was inside you the sensations kept getting stronger and more intense until I just burst! I know there wasn't anything I could do to resist, that cumming in you like that was an uncontrollable reflex, but I still feel kinda bad about it. You're the one who might have to deal with the result of my body's need to get its rocks off for the next nine months."

"There's no need to apologize - I know it's not your fault. You're just as much a product of evolution as I am, and my body clearly wanted to be impregnated today," she said as she slid her panties back over her flared hips. The crotch darkened slightly as his cum continued to ooze out of her, and then she slid her skirt up her shapely legs and back into place, completing the sexy look that had helped draw Mason's attention to her in the first place. Now, however, the shapely torso hidden by that skirt had accomplished its evolutionary purpose; it had been filled with Mason's cum and was working hard to complete her impregnation even as she continued to respond. "Once you were inside me my body was rewarding me with so much pleasure for letting you do it that all I could do was squeeze your cock up into my pussy over and over again, even knowing what would happen as a result. My body was too determined to get your genetic material - it's designed to tease it out of you, and your body is designed to lose control and pump me full of cum, so of course there's no way you could resist."

"Well, I guess there's nothing we can do about it now, anyway," Mason said, pulling her into a friendly half hug that lacked any of the sexual intensity of his embrace just minutes before. "Damn, Human Reproduction is a bitch. See you in class on Monday?"

End of Chapter 1