Chapter 4

Lucy [16] woke up first, stretched and looked over at Amy [16] laying face down beside her. A shaft of low autumn sunlight from a crack in the curtains illuminating her gorgeously long dark hair. Lucy brushed it aside, softly kissing the back of Amy’s neck. As she gradually kissed down Amy’s spine, her breasts stroked the back of Amy’s arm, making her nipples harden; Amy stirred in her sleep. Lucy pushed down the white cotton sheet, exposing Amy’s bare taut buttocks. Lucy kept kissing lower and lower; holding each buttock in turn. Lucy adored Amy and would do anything to pleasure her friend. As Lucy pulled Amy’s buttocks apart to insert her tongue, Amy awoke, spreading her thighs wider and lifting her bottom up to Lucy’s eager mouth.

Lucy slipped one hand forward, between the quivering buttocks, still expecting to feel soft warm wet pussy – but no - just a smooth dry crotch, just like her ex-boyfriend. Then her fingertips encountered cock on a massive scale – it all came flooding back.

Background I have to admit that this story is not original – it takes the teen characters, Lucy and Amy, from a story uploaded by Drew Robbins from Indiana.

In Part One, Amy visits a secret animal research laboratory on a school trip and foolishly consumes an experimental green liquid containing Horse-DNA, testosterone and something else. The following day she feels a little unwell, but sitting in the bath is horrified to see her hardly-used pussy ‘heal over’ and this enormous horse-cock sprout from her loins.

After Dr Michaels confirms her worst fears that her DNA has changed, probably permanently, Amy ‘comes out’ to her best friend Lucy. After the initial shock, Lucy agrees to move in with Amy – the two develop an unusual lesbian/bi-sexual relationship.

In Part Two, the friends experiment with Anal and Cuntal penetrations – Lucy adores both.

I have taken this situation forward into the story you find here – enjoy.

Partway through writing this episode I discovered Part Three, in which we meet Scarlet. I won’t spoil the surprise, but if you need help visualising a girl like Amy but with more anatomical differences there is some excellent work by Futanari artists on xhamster. I have trouble understanding how you would ever satisfy such a girl but might include her in a future story.

Back in Bed Amy rolls over, trapping Lucy’s head between her thighs – forcing the horse-cock into Lucy’s face. Lucy crawls up the 12” of rigid engorged prick – the entire shaft exposed from its fleshy sheath. Lucy is amazed she can now get the entire cock-head in her mouth – her muscles are definitely relaxing with every sip of sperm she swallows. Amy scoots around under her lover, lifting her legs so that Lucy is now straddling Amy’s face – a moist cunt just inches from her eager tongue. Amy loves to eat out Lucy – her cunt feels so soft and open, especially when Amy inserts a few fingers into her arse. Only yesterday Lucy flinched at two fingers, now all four comfortable fitted – Amy was fisting her best friend’s arse.

Lucy stopped sucking cock for a moment: “Oh shit, that feels amazing – how many fingers have you got up there”? She looked back over her shoulder, amazed to see Amy’s entire fist vanishing up her own arse – just like those photos of vets with their arm up a cow. Suddenly she had a deep animal desire for this horse-cock, not just sucking it and drinking Amy’s cum, but fucking it with all her young body.

Lucy pulled Amy’s arm from her arse and twisted around so that she was balanced above the cock head.

Lucy gets an Anal

“Are you sure?” panted Amy. Lucy didn’t answer, just lowered herself onto the horse-cock. She had never felt so full. The cock was up her arse – she was riding it; lifting up and plunging back down.

Once the cock-head was in, Lucy screamed but kept on pushing down. That first time she stopped, panting, sweat running off her nipples, with about half inside her: “Oh God, Oh God, Oh God” she mumbled, “Where on earth is it all going inside me?”

The girls had only a hazy knowledge of human anatomy, having both flunked biology at school. The biology syllabus was just getting to the human reproduction cycle when the science teacher was sacked, caught fiddling with a small boy. The school persuaded the nice Maths teacher to stand in, but he just read the words off the screen, trying to avoid the gaze of a dozen pubescent girls masturbating noisily at the back of the class. He stopped the lesson when one of the little sluts leapt up onto a desk, holding her cunt lips apart, demanding “Inseminate this.”

So they never really learnt how flexible the intestines are, and probably only Dr Michaels could explain how Lucy was now able to take the entire 15 inches of horse-cock up her arse. Both girls were soaked in sweat and Lucy’s pussy juice; then the horse-cock started cumming deep inside Lucy – Amy was certain she saw Lucy’s breasts increase at least a bra size, as she hugged her friend through their best simultaneous orgasm ever.

Both girls were crying with emotion – Amy held her friend’s face – kissing away the salty tears, as she erupted deep inside Lucy’s body – horse-cum dribbling down her thighs as she pulled out, completely spent.

Lucy walked around in a daze for the rest of the day, stroking her bottom, conscious of the changes going on deep inside her body.

Examination One day Dr Michaels rang: “I’m sending a car over for you Amy, I’m a bit concerned about the effects of that horse DNA on your metabolism. I’d like to run some more tests.”

Lucy was out when the dishy lab technician arrived to collect Amy; otherwise, he might have ended up tied to the bed for the weekend, but Amy was too worried to play with him.

At the research centre, Dr Michaels ran the usual battery of blood pressure, height, weight tests and a thorough breast examination that Amy thought was a bit excessive.

He handed her a glass beaker “I’d like a sperm sample, you can use my office.”

“But, erm, I don’t think I can fill that. Anyway, Lucy always plays with my horse-cock. I’ve never, err, tried masturbating it.”

“Don’t worry, miss. You’ll be fine. There are some magazines in the top drawer. I’m sure you’ll find something suitable to arouse him.”

Lucy pulled off her jeans and white panties and sat on the cold leather office chair. Horse-cock stirred as her hot bottom and thighs warmed up the cold seat. Sure enough in the top desk drawer was a pile of nude magazines. Most were quite old, showing mature ladies with huge busts in ridiculous poses, which held no appeal to Amy, or horse-cock. Near the bottom of the pile, Amy found what looked from the cover to be a stuffy medical journal, but inside was pure joy. Photographs of young girls in tight white jodhpurs and black riding boots, saddling up their horses. Over the page one beauty was standing up in the stirrups, her thighs and tight shapely bottom presented to the viewer. Amy had never seen horse-cock rise so quickly – it slammed against the edge of Dr Michaels’ desk. This was no time for measurements, but she was certain it was longer and fatter than yesterday, probably now a full 18.”

Amy carefully took hold of the cock shaft in one hand, just behind the head and tried to aim it at the tiny glass beaker in her other hand. Horse-cock tried to teach Amy how to masturbate it – long slow strokes, right up to the tip, and back down again to the balls. But it was never going to work; after a few swift strokes horse-cock was gushing sticky white sperm all over her hands, the desk, the magazine and by luck some ended up in the beaker. She licked her sticky fingers – wow, it was so sweet and smooth as it slipped down her throat. Now she knew why Lucy loved to swallow so much.

When Dr Michaels returned a few minutes later, Amy was all cleaned up and dressed: “Sorry about the mess on your desk. Can I keep this old magazine? You seem to have plenty.”

The lab technician drove her home, with a supply of screw-top jars and a small fridge to keep them in. He called every Saturday morning to take the sperm samples back, not knowing that most of it had been sprayed up into Lucy’s arse prior to dripping out into the jars.

Once Lucy had been filled with horse semen at both ends, it rekindled a childhood love of horse riding. Lucy persuaded Amy to sign up for lessons at the local stables. They couldn’t wait for Sunday; getting very aroused over photos of the young girls, but especially the horses. Amy had hardly left the flat for days, afraid that someone would notice the bulge between her thighs, and she had nothing to wear.

Mothercare All her skirts were so short they exposed the horse-knob when it relaxed down her thigh and her jeans were so tight she was afraid of catching it in the zip (panties were useless).

“How do men avoid that?”Amy asked no one in particular. She longed to ask her Dad, but he was going to be the last one to hear about her little experiment.

Eventually, she found an old pair of baggy corduroy trousers with a button fly in the back of the wardrobe; paired with a sloppy tee shirt.

Shopping in town, Amy felt strangely attracted to pregnant women – she could feel horse-cock twitching against her thigh.

“What about the Mother & Baby Shop?” suggested Lucy, dragging her friend in the front door, trying to avoid the gaggle of heavily pregnant women stroking each other’s bumps.

Amy is bending down to a low shelf – what stupid merchandising – looking for a pair of pregnancy dungarees in her size. She was always a trim size 8 before the ‘accident’, and from the back her shapely, tight arse still was (unlike Lucy’s, which was beginning to gape from the 3 times a day sperm collection).

Lucy exclaims “watch out” as a pretty teen, with bright blue eyes, massively pregnant, only a few days to go, doesn’t see Amy and collides with Amy’s upturned arse. Amy stands up, still holding the dungarees, turning around – the girl is clearly embarrassed: “Sorry I didn’t see you down there; I can hardly see my feet anymore.”

She compares the shape of their obvious bumps: “I had a pair of those dungarees, up to 5 months, I guess. They hold it all in really comfortably. Amy watches in horror as the girl’s bump moves. “That’s OK you can feel him kicking if you like.”

Amy touches the bump on the girl’s tummy, then gaining confidence, slides her hand down between the girl’s hot thighs.

Blue Eyes: “God you’re making me all wet – even my boyfriend has stopped touching me like that – keep doing it, you’ll have a baby in your hands.” Amy’s nipples harden, horse-cock threatens to split the trouser stitching.

Lucy is standing behind Amy, shielding their groping from the other shoppers: “Bet you want to try this then, gorgeous.” She undoes Amy’s fly, releasing the swollen horse-cock into the girl’s hands.

“Oh my God” she exclaimed, bent down and took the first 3 inches into her mouth. She sucked like a vacuum cleaner, both hands massaging Amy’s balls, slathering the horse-cock in spit. Amy tried her hardest to remain calm in this shop full of pregnant women but shortly had to hold onto the girl’s head for support as she released rope after rope of steaming hot cum into the girl’s mouth.

Blue eyes staggered to her feet, wiping away a drop of spunk that missed her mouth: “That was awesome; here give me a kiss.” The girl swapped the still-hot sperm with Amy, both swallowing each other’s face in a passionate embrace.

“OK, OK, break it up you two,” Lucy demanded. “You know that stuff might not be good for her in that condition. Can I have my girlfriend back now?”

The girl staggered off, holding her bump, certain that the kicking had changed. The Maternity Unit was certainly in for a surprise when that little girl was born with a full mane of shiny dark hair (her mum and dad were blonde)...

Ann Summers It was obvious to Amy that Lucy’s arse gaped open most of the day; Lucy kept touching herself, hoping for something to fill it. She had tried most of the bottles and spray cans in Amy’s bathroom, but she complained they kept falling out. The girls giggled outside the local sex shop, daring each other to go in. Inside, Lucy browsed along the high shelf of sex toys, trying to find the right-sized anal plug.