She made a show of checking his eyes and ears, and elbows, then slyly said imperiously, "Okay you need to take off your pants now."

"Why?" he asked, startled at the sudden claim.

"Because I'm the doctor, and I have to examin your <i>whole</i> body," she said, pointing at the fake surgeon's mirror strapped to her forehead. "So pants off mister!"

"Oh, okay doctor," Nathan said, pulling down his pants, revealing some tasteful rocket ship briefs around his boyhood.

"Take off your panties too," Sara said, looking at the mysterious little bulge in them between his legs.

"My panties?" Nathan replied skeptically, "You mean my underwear?"

Sara blushed, looking up at him, saying abashedly, "Yes, those. My mommy always calls them panties."

"Why?" he asked, "You wanna examin my <i>penis?"</i>

"Your what?" she asked cluelessly. Before he could embarass her more, she added hastily, "Yes I want to examin that too. Just to make sure your peen is all healthy."

"Okay, I guess," Nathan said, fingering his briefs and sliding them down, kicking them off his slim legs.

"Alright now," Sara said in a businesslike tone, squatting down to look between his legs. An eager glee flooded into her as she was finally gonna get to see what a boy looked like down there. He didn't have a slit was the funny thing. Just this little bump, and a little... hose sort of thing.

She inspected it with her highly official doctor magnifying glass, and just looking at it was strangely enticing. There was a wild spicy smell coming from it too, and her own pussy was starting to feel squirmy.

"I uh... t-tell me if this hurts," she said, poking at it with a finger.

Giggling, Nathan said, "No, it kinda tickles though. You want me to pee or something?"

"Could you?" Sara asked hopefully, then blushed again and stammered, "B-because I'm the doctor and I wanna make sure you pee okay."

"You wanna <i>watch</i> me pee?" Nathan asked, lip curling a little, even though desire was rising in him as well, to be closer to her, more exposed.

"Just to see if you're healthy!" she stated, "Y-you can even watch me pee too, so it's not weird!"

One way or another, she and Nathan snuck into the bathroom together, giggling like imps. He pulled down his pants again, and said, "I never saw a girl pee before. This is how I do it."

"Aren't you gonna sit---" she stated, halting as a strong stream of urine emerged from the little penis he was pinching, and cascaded in a graceful parabola to the toilet water below. "Oh, it just... comes out of your penis," she said, engrossed.

"It doesn't come out of yours?" he asked curiously.

"No, I... I don't have one," she said, as he finished peeing, and shook off his penis, then dabbing just the hoselike tip with a toilet paper. "I'll show you," she said with determination, sliding off her dress, and then her panties. Then because her shirt was sorta in the way, she took that off too, and was totally naked in front of him.

"Wow, you don't have anything down there," he said in awe, staring at her crotch. She wanted him to stare more.

"I have something," she protested hopefully, reaching down and spreading herself. "...you can't see it since I'm not lying down, but I pee from there too," she concluded quietly.

"I can't?" he asked, still looking.

"Yeah, it..." with a hand on the counter, she could tilt her pelvis forward, until he could see her sensitive vulva being spread. "See how I'm... different down there?" she asked.

"Yeah, you sort of... open or something," he said, "With your fingers. Is that where the pee comes out?"

"Y-yeah," she said, blushing and loving this, "I don't usually hold it with my fingers though, I usually just pee."

"Well, show me then!" he said eagerly, still naked from the waist down, his penis looking a little plumper than before.

"I can't," she said looking at the toilet in frustration, "I have to sit down when I pee and you can't see it."

"...do it in the bathtub?" Nathan asked slyly.

Soon Sara was in the bathtub, legs splayed to either side, spreading her labia with her fingers to show Nathan. "Here goes..." she said, feeling the urine well up in her. She was breathing harder, watching him watching her, as a trickle of pee started to fountain out of her groin. "Nh, it's getting all over my... butt," she said in satisfied dissatisfaction.

"M-maybe doing it in the bathtub was a bad idea?" Nathan asked nervously, but not ceasing watching her peeing.

"No I'll... clean o-Off" she said, clenching so the pee started really spraying out of her, trickling down her pelvis and the wall of the bathtub. "Pretty cool, huh?" she asked smugly, "It just comes out of me down there."

"Yeah," he said distractedly, as her pee trickled to a halt, "...can I play doctor next?"

"Because you wanna touch my pussy?" she asked with a teasing giggle.

"Your what?" he asked, and she met his clueless eyes for a moment, before he said, "Like you touched my penis. I wanna use my fingers to open your... place."

"Mommy called it a pussy," Sara said uncertainly, turning on the bath faucet enough to drench her pelvis in cold, cleansing water. "And she said never to show it to boys, or let them touch it."

"Oh," he said, sagging, looking visibly disappointed. "I'll just---"

"And that's why I'm gonna let you touch it," she concluded. "You don't even have to be a doctor. We can just touch each other's... places as much as we want. Just let me get mine dried off."

"Can I dry it off?" he asked, as she reached for a towel. Tossing him the towel, Sara stood up in the bathtub, her groin dripping, saying, "Sure, go ahead, just don't rub too hard with the towel."

He didn't, and in fact he was too careful, barely touching her butt, belly and legs as he tried to towel her off. "You can push, just don't rub," she said impatiently, pulling his hand against her towel covered groin. He did, and soon the towel dropped away, and his hands just explored the soft flesh down there, spreading it, poking onto it, feeling at her belly, and as he got more confident, her butt. She kept breathing harder, because this aching desire was flowing from her groin.

She looked at his groin again, saying, "Wow, your penis!" because it'd gotten really big, and was sticking out of him like a pole!

"Huh, it... it just did that," he said, pulling away from her groin to look at his own. "It usually gets small after a while, when I wake up like this."

"Can---can I touch it a little?" she asked hopefully. Before he could answer, she just kind of... wrapped her hand around it. It was so soft and velvety, yet unresisting and hard. "Oh, that feels... funny," Nathan said, unconcsiously thrusting into her hand.

"Bad funny?" she asked, looking to him worriedly.

"No, good funny. C-could you squeeze it?" he asked, "I liked it when you..." and she did, while a pleased groan came from his chest.

Just then the door to the bathroom opened, and the sitter was there, saying, "Aha, there you little---" They scrambled to separate, slipping on the bathroom floor so she fell to her butt.

"We were playing... doctor," Sara said lamely, face beet red.

"Oh... oh wow," the babysitter said in less than an admonishing tone, but more one of wonder, "You kids are really old enough to do that?"

"Play doctor?" Nathan asked in confusion.

"No, make babies. Have sex," the babysitter clarified. "That's why you wanna be naked together, is because it'll make you have sex."

"Ohh," Sara said with a cautious nod, "What's sex?"

With a devilish grin, the sitter said, "Meet me in your room, and I'll show you." Stripping off her own pants and panties, the babysitter added, "No clothing allowed," then scarpered off.

The babysitter's mature, hairy groin, and her round, full breasts made both Nathan and Sara feel funny, as they joined her in Sara's bedroom.

"Alright, you sit on the bed, on your butt," the sitter instructed Sara, who climbed up and sat there curiously.

"And you sit in her lap," Sara said to Nathan, "But face her, instead of away from her. Just wrap your legs around your hips, so your naughty bits are just about touching each other."

"Ohh, okay," Nathan said, and Sara kind of understood too. It made sense if they both liked touching those places, then they should touch them together.

With Nathan straddling Sara, the feel of his testicles pushing up against her labia was very enticingly distracting. "We sure are... sexing," she said nervously, feeling strangely unsatisfied within her groin.

"Having sex," the sitter corrected, handing Sara a small bottle of lotion, "Now I need you to put some lotion all over his penis. Make sure it's good and hard."

"O-okay," Sara said, squirting out some lotion onto her hand, then wrapping it around his penis again. If Nathan had lost his erection, the merest touch of those warm, lotion covered fingertips brough him swelling up, stiff at attention.

"Wow, it... feels really weird as it gets bigger," Sara said, rubbing in the lotion, as the penis fought in her grasp to swell and jerk in place.

"Don't rub it in too much, mostly you just want it <i>on</i> his penis," the sitter said. 

Blushing, Sara got another little bit of lotion, and slathered it over his penis. "Like this?" she asked.

"What do you think, Nathan? She doing good?" the sitter asked.

Flushed, panting, Nathan said, "Yeah, it feels <i>really</i> good..."

"Oh, well you ain't felt <i>nothing</i> yet," the sitter countered. Then reaching between them, she took Nathan's penis in her slender fingertips. "Scoot back a bit," she prompted, as his erect penis bumped tantalizingly against Sara's belly. He did, and the sitter angled his penis down to point right at Sara's pussy. "Alright, scoot... together a little bit," the sitter prompted, and ensured that Nathan's penis would push up <i>right against</i> Sara's pussy.

"Ohh that feels..." Sara and Nathan said at the same time, as Nathan unconsciously bucked his hips, pressing strongly against Sara.

"Hold still, I need to get you..." the sitter said distractedly, until something seemed to shift within Sara's pussy, that Nathan's penis just wedged right into. Something <i>important.</i>

Standing back, the sitter said, "Alright, now lie on top of her. Your penis wants to push against her harder, doesn't it?"

"Y-yes, it..." Nathan shifted, and slid his hips forward, making Sara gasp in surprise.

"It's... not stopping!" she squeaked, as Nathan bottomed out in her, laying atop her with a commanding weight that pushed her into the bed. "Oh it... stopped," Sara said cautiously.

"Hm... sit up again Nathan, just so you can both see Sara's pussy," the sitter instructed.

Nathan did, and the sitter declared, "Remember his big old penis, how big it got? That's all inside you right now."

"H-how?" Sara said, staring at where Nathan's penis just... ended at her pussy.

The sitter just touched Sara's belly softly, saying, "You can feel him in here. That's where your baby's gonfna grow, once he climaxes inside you."

"M-my baby?" Sara said in confusion.

"Yeah, he has to pull out just a little, then push back in," the sitter explained, and as Nathan did it, the pleasure flowed through Sara all over again, through both of them judging by Nathan's moan. "Keep doing that over and over again, and Nathan's gonna climax," the sitter said, "He'll squirt out a special stuff from his penis, called semen. Once he squirts it into you Sara, his sperm are in it. Little cells of his that'll swim around inside you." 

It was hard to concentrate on what the sitter was saying, because Nathan wouldn't stop <i>thrusting</i> into Sara. He pressed her hips down against the bed, and she humped them up, needing to feel him sliding in and out in and out.

"Inside you is an egg, Sara. Every girl has them," the sitter said coyly, fingering herself at the children fucking on Sara's bed, as the babysitter sat on it next to them. Sara couldn't pay attention to where the sitter was sitting, only this penis and getting it to thrust and thurst into her.

"Once his sperm are inside you, they'll swim around till they find your egg," the sitter continued, "And it'll start turning into a baby then. Your belly's gonna get bigger and bigger, as your new baby grows in there. Till it's <i>really</i> big and round," the sitter pantomimed a gravid belly in front of her own slim belly. "Then one day your whole belly's just gonna start squeezing and squeezing. His penis's in your <i>vagina</i> right now, and your baby's gonna start squeezing out through <i>that.</i> You won't be able to stop pushing. It'll be all you can think about.

"Then when your baby is out, you'll be a mommy," the sitter touched Sara's sweating forehead as Sara panted there, needing coitus, but not sure if the sitter was just teasing her or what. "And you'll be a daddy," the sitter declared, touching Nathan's forehead. "Just keep thrusting in and out, and you'll start spurting your seed inside her. And once it's inside her... she'll start having your baby. It'll just start growing inside her, changing her into a mommy. That sound good?"

"N-no it," Nathan whined desperately, dragging his shaft in and out, "I can't stop..."

"Don't stop then," the sitter cooed, "Put a baby into Sara, and then we can talk about what's gonna happen."

"I can't... stop either... he's <i>inside</i> me!" Sara cried out needily.

"You wanna baby, don't you?" the sitter asked Sara slyly, "Just thinking about your belly being big and round, and <i>squeezing</i> makes you feel all tingly inside. Knowing what his' penis's gonna <i>do</i> in there."

Sara moaned desperately, and humped against him as if her life depended on it.

The sitter let them fuck then, and the kids hugged each other and breathed hard as their hips rolled together with a primal instinct that had just awakened in them. His penis slid in and out and in and out. She grew more and more incensed, until Nathan blurted out, "I can't---! (thrust) My penis's... (thrust)"

"Just let it happen to you," the sitter purred, "Just keep thrusting until you explode inside her. Get ready, you're about to give her a baby."

"My semen..." he moaned incoherenmly, humping and humping and then <i>jamming</i> his hips against her.

"What are you...?" Sara asked, feeling his penis give a mighty flex within, then another.

"I--I'm..." Nathan said, then he huffed out a moan as something burst inside Sara. 

"I-I can feel you doing it," Sara said, shocked as the warm, slimy fluid bloomed deep into her belly with every jerk of his penis.

"You're pregnant now, Sara," the sitter said in an almost grateful tone, laying back with her hand between her own quivering hips, "That's his seed, and it's changing you inside, to have a baby in there."

"I-it feels... warm," Sara said lamely, looking up at a now worried looking Nathan.

"How's it feel Nathan, to see Sara changing into a mother right in front of you?" the sitter asked Nathan.

"She looks... really good, but... the same," Nathan said uncertainly.

"It's subtle at first," the sitter explained, "But you'll be changing a lot, Sara. Your insides growing big for the baby, you'll be getting hungry to feed it, and your pussy's gonna get ready to stretch open. Your breast's'll grow, and start producing milk In nine months, so... maybe a little bit before school lets out."

Sara whimpered at that, not entirely in fear, so the sitter asked her, "How'd you like that? Be sitting there in class, and then you can't stop squeezing your belly, pushing out your baby. You'd have to take off your clothes super fast, so you could stretch your legs open, and show everyone your pussy as you can't stop squeezing a baby through it."

"I'm gonna <i>do</i> that," Sara moaned passionately, sinking back and squeezing compulsively around Nathan's softening penis.

"Tomorrow, you can watch him put a baby into me," the sitter replied in heady lust.

...

Sara couldn't believe it. Nathan was just putting a baby in their sitter. She watched him thrust and thrust into the panting sitter's hips, his little penis just burying into her big hairy vagina. Sara was fingering herself desperately, wishing she could have that penis inside her, but so amazed at just seeing it vanish in the sitter. Then Nathan pushed up close and grunted intensely. "Ohh, see Sara?" the sitter called out as the base of Nathan's penis started <i>pulsing.</i> "He's putting his semen into me. I-I'm having a ba.. ba..baby~!"

The sitter grabbed Nathan in her legs then and pulled him right against her. "Woah!" Nathan said in amazement, "She's just squeezing all around me!"

The sitter didn't say anything, and they just lay like that for some time, before Nathan said, "Oh, she stopped."

"Just..." the sitter gasped in utter satisfaction, "Just enjoying you putting a... hoo boy, a baby in me. Me 'n Sara are both gonna have big tummies... and we're both gonna lay there, pushing out your babies for you. T-t-two babies, one from me one from her... vagina.

"I wanna push out a baby," Sara moaned, fingering herself again.

"He can do you again tomorrow," the sitter said hopefully, "Just to make sure."

"His... his penis?" Sara asked hopefully.

"In <i>your</i> vagina!" the sitter concluded joyfully.

...

Sara was waiting for the Nathan and the sitter to arrive, and she was putting her hand under her pants and panties, and rubbing her soft, warm baby place. "Uhn... wanna feel the sliding," she moaned, sliding a finger into her vagina, "Wanna feel his penis again..."

Once everyone was together, Sara said hastily, "Can we do it now? I I really want your penis Nathan like all day and I'm getting all gooey even and---"

"Oh, you don't need lotion, then!" the sitter declared in surprise, "Your vagina's making all the lotion he needs."

Sara put her hand under her pants right in front of them, sticking her finger into her gooey passage, quietly moaning, "I wanna though. His.. his penis's gonna slide in me, and squirt in me."

"He has to get erect first," the babysitter cautioned, looking at Nathan, "Is your penis all big yet?"

"Y-yeah," Nathan said distractedly, staring at the masturbating Sara, hunched over with her hand in her pants.

"Alright, just pull your pants down, and you get your penis in her soon as you can. Just lay on the floor Sara, and let him <i>do</i> you!"

Sara lay down, and wiggled out of her panties and pants, then lay there rubbing herself again, her hunger flaring powerfully as her friend pulled down his pants enough to expose that bobbing penis of his.

"Spread yourself, Sara," the sitter instructed, "Show him your insides... where he's gonna put his penis."

Sara didn't know how, so the sitter reached down, and a powerful tingle rose at the sitter's touch, two fingers spreading Sara's needy labia wide. "Right here," the sitter said to Nathan, "Put your penis in here, and ejaculate all your seed. You're gonna use your penis to make this girl fat with child, and giving birth to your baby."

Nathan tossed his pants away, then knelt down, crawling forwards hungrily. Sara was panting and staring between her legs as his dangling penis approached. Then it pushed against her pussy, then wedged in there, then slid up inside her in one smooth stroke. 

"Nathan~ your penis!" she said, eyes going distant as she felt it slide and stretch her in there, then start pumping in and out. "You're already..."

That was all that needed to be said. Soon the two children were holding each other and humping with determination. Both were panting, and sweating, and Sara couldn't stop this incredible tingle from building inside her as he slid along her inner walls, and she had to wrap around his penis.

More... more... more... and then Sara had to lay there, dull-eyed, open mouthed and panting as her vagina just started squeezing around him all on its own. She couldn't stop! It felt so good! Rushes of pleasure rolled through her, and she couldn't believe his penis was in there. Her vagina had barely calmed down, when he pushed deep and held inside her. 

"Oh... gonna put a baby in me?" Sara asked serenely, fumbling around behind Nathan's butt to feel at the base of his penis. He breathed raggedly in reply, and the base of his penis started <i>flexing</i> under her fingers. His shaft started kicking inside her, and Sarah breathed an amazed sigh, as she felt him start squirting seed into her. "Oh, Nathan..." she said distantly, wishing she had some better way to describe how she was feeling.

The babysitter had a way to describe it. When Nathan thrust into her for the final time, and moaned as he started to orgasm, the sitter held the boy and murmured to him, "That's a good boy, just let it out. Squirt your semen into me. You're putting a baby in me, Nathan. How's it feel?"

"Gooood.." Nathan moaned in drunken pleasure.