It has become a well-known fact that the Animalian virus has many unusual properties, particularly involving age. A single dose can uplift an animal or convert a human, but they would remain the same age as they were before they were changed. Though with animals, they would become the equivalent age in human years. However, a second exposure from an Animalian outside of the exposed one's age group will cause them to either age up or age down until they are in their physical prime, which typically appears to be in the early 20's.
Quite obviously, double-dosed who have become younger are far more common than double-dosed who have become older. There were many adults who would want to have a second chance at youth, even if they weren't the same species as the first time. And there were many who took a double-dose to make sure whatever ailment they had before was permanently gone.
Most parents would want their children to avoid getting a second dose until they fully matured naturally. Children were in such a rush today to grow up fast and skipping their childhood could be an awful mistake. But there were some noted kids who have ended up double-dosed, usually by accident. Abigail Brown and Sarah Wesley had been only 14 years old before second exposures made them into an adult mare Animalian and husky Animalian respectively. Marcy White was only 10 years old, but exceptionally smart enough to skip a few grades. Thanks to Chilly, she became an adult polar bear Animalian and finally felt like her body matched her mind.
The current record holder for youngest double-dosed converted was Milly. She had been only a little over three years old when an accidental drink of contaminated milk caused her to grow from a mousy toddler to a mouse woman. Milly had been a particularly interesting case as she had developed a mental and emotional maturity to match her adult body. Scientists at Horizon theorize that the same process that gave uplifted animals intelligence had the same effect on Milly's underdeveloped brain. Though it had caused a stir at first, Milly was able to qualify as a legal adult. She had completed her GED, worked at the Animalian School of Modeling, and had recently married Lenny. Asides from her actual chronological age, she seemed no different from any other young woman, mouse or not.
But then Milly learned she wasn't the only toddler who double-dosed by accident. There had been a set of sextuplets who had be changed into adult horse Animalians rather recently. However, since they were six months older than Milly, she was still holding onto the record for youngest double-dosed converted. Milly had plenty to do herself, including house hunting and getting ready for the Easter/Earth Day event next weekend, but she really wanted to meet these six Animalians who had origins similar to hers.
She had called the reeducation center where she had spent her formative days after her second dosing and arranged for a time where she could meet the sextuplets. She wondered briefly if she should dress casually to show she too was still a kid inside or professionally to show that she was an adult as well. She decided on the latter, these siblings were learning to be adults and they didn't need her patronizing. A business suit and a little makeup and she was ready to meet them as equals.
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The sextuplets were being taught in the same classroom that Milly had been in, so she knew where to go. When she walked in, all six of them were sitting or standing around the classroom. Their manes and tails were brown, though at various shades, but their coats had more variety. One particularly big stallion had a very dark coat. If the room were dimmer, it would look black, but Milly could see it was a deep brown. There were a pair of mares who had white muzzles and chestnut fur. The two of them of them were so identical that only their clothes and their ponytails on opposites could tell them apart. There was also another similar pair, though they were both stallions. Their hairstyles weren't different from each other, but their choice of clothing was in bigger contrast with the first pair. They stood apart from the first stallion by being a little shorter and having white 'socks' on both arms and legs, also their fur being a straight chocolate brown. The last horse was also a mare, but she had white covering her arms and a star on her forehead, yet no white on her muzzle. The rest of her fur was more of a sandy color
As horses, they were a good bit taller than Milly. But Milly had known plenty of big Animalians at the Modeling School. And her husband having gigantism has made tall people not that unusual to her. "Hello, my name's Milly," she said, "I haven't gotten any of your names yet."
"We're the Hansons," said the darkest stallion, "I'm Abraham, I'm the oldest."
"I'm Blythe," said one of the identical mares.
"And I'm Coye," said the other identical mare.
"My name's Damien," said one of the identical stallions.
"And that makes me Elijah," said the other identical stallion.
"And that leaves me, Faye, the youngest," said the brightest mare.
"Was that all in order of birth?" asked Milly.
"Yeah, the alphabet theme gives it away, doesn't it?" asked Blythe.
"Still, if we had been quadruplets like Mom wanted, we'd probably all start with the same letter," said Coye.
"Your mom was expecting quadruplets?" asked Milly, a bit surprised. She had read that the older a woman was, the more likely she was to have multiple births. No one was really sure why.
"We probably started out as four, but then some of us split in the womb," said Damien.
"So we've got identical and fraternal quadruplets here," said Elijah.
Clearly the middle sextuplets were the identical ones, the twins of the bunch. Milly briefly wondered if she would be producing so many babies at once. But that wasn't what she was here for. "So, did having all of you at once had something to do with, er, your exposure?"
"Well, part of it," said Faye, "Carrying all of us did a number on Mom's body. Dad was planning on getting Mom converted and everyone else as well."
"But then we ended up taking it a lot further than they were intending to," said Abraham.
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The kids had heard Mommy and Daddy talking. Mommy hadn't been feeling good lately, she got tired very easy. Daddy had looked a little worried, but then he was excited about something. He was talking about big changes, moving to a bigger place. To the kids, it sounded like Daddy was planning some sort of surprise party and parties usually mean cake. So when Daddy brought the box home and acting excited, the kids assumed that the box had cake in it, even if it was the wrong shape. And being kids, they wanted to take a little taste of it, so they took the box back to their room.
When they opened the box, they were a bit disappointed to only find a jug in it, a jug with a horse's head printed on the side. "That's not cake," said Damien.
"What is it?" asked Coye.
"It looks like a milk bottle," said Blythe.
Abraham struggled with the jug's cap for a while, but eventually managed to get it open. He looked inside and sniffed it. "It is milk," said Abraham.
"Why did Daddy bring home milk in a box?" asked Damien.
"Well, I'm thirsty now," said Elijah, "Can we drink some?"
"Oh, I'll get the teacups," said Blythe, heading to their play table and getting the cups she and her sisters used to play tea.
"I don't want to drink tea," complained Elijah.
"We're not having tea, we're having milk," said Faye.
"Oh, ok," said Elijah.
The milk jug was a little awkward for Abraham to handle, but he did manage to get some milk into the cups with only a little spilling. The kids sipped at the milk in their cups. "This milk tastes funny," said Damien.
"It's making my mouth feel funny," said Coye.
"I'm feeling funny all over," groaned Abraham. Before long, the kids were groaning as their bodies changed. Fur was growing over them as tails were growing out of their backs. Their shoes got uncomfortable so they took them off, revealing their feet were turning into hooves. Their heads were also changing, their faces pushing out into muzzles as their ears grew longer and moved up their heads. In a few minutes, the six kids had become six foals.
"Hey, we're ponies!" said Blythe excitedly.
"But I don't wanna be a pony," complained Damien.
"How did we become ponies?" asked Coye.
"It must have been the milk," said Abraham, "I bet it's magic milk."
"I'm still kinda thirsty," said Elijah. The others gave him an odd look. "What? We're already ponies."
"That's true," said Faye, "What else could that milk do to us?"
"It might make us ponies all the way," said Damien.
"It would have done that the first time, woudln't it?" asked Coye.
"There's only one way to find out," said Abraham. His hoof-tipped fingers made it a little harder to grip the handle. But he also felt a little stronger and the jug was already missing milk so he could lift it easier. Holding the teacups wasn't too hard for the foals and their new mouths could still sip from them.
"Anything happening?" asked Elijah after they drank again.
"I don't feel like I'm changing," said Blythe.
"Actually, I feel a little good," said Faye.
"Are you guys getting smaller?" asked Abraham.
"No, we're still just as tall as you," said Damien.
"But something looks smaller," said Coye.
It was about that time that they noticed their shirts were riding up their stomachs and their pants were getting tighter. "Hey, we're getting taller," said Elijah.
"We're getting bigger," said Damien, sounding excited.
"I think we're getting older," said Abraham. The six of them were looking less like toddlers. By now, they looked 8 years old.
"My shirt's getting too tight," whined Blythe.
"Help me get mine off," said Coye. The two of them yanked at each other's shirts, ripping them quite a bit as they tried to get them off. The others were soon trying to get their clothes off too. Some of them were able to get them off, but most of the clothes ended up being ripped off.
The six foals stood naked, facing each other. They were still growing, making the room look smaller. The baby fat on their bodies was fading away as they got taller, their arms and legs looking leaner. Eventually, Abraham looked at Faye and asked, "Faye, what's that on your chest." He felt his throat in surprise. His voice sounded deeper than before.
Faye looked down to see her nipples were sticking out and the area around them was looking more puffy. She pressed her hands to them, feeling an unfamiliar pleasure. "I think...I think I'm growing boobies," she said. Her voice was also deeper, sounding less childish. She felt less childish as instinctual knowledge was entering her head.
"Well, they look..." said Abraham before his voice cracked and he stopped. But looking at his sister's growing breasts did interest him. Then he felt a new feeling. Looking down, his wee-wee, which disappeared into a pouch thing, was coming out again, but it looked different and longer.
"Hey, your penis is showing," said Damien, not quite sure where he heard the word from.
"Your penis is showing too," said Blythe. All of her brothers were sporting hard-ons and the sight of them was getting her excited.
Elijah tried to push his back in, but he moaned instead. "This feels good," he said as he started stroking his shaft. The other colts were soon stroking their shafts.
Coye had started rubbing her budding breasts and said, "This does feel good." The fillies were massaging their breasts, which were growing bigger in their hands. Pretty soon, a new sensation got their attention and they reached down to feel their changing vaginas.
Meanwhile, Mr. and Mrs. Hanson had noticed the missing box. "How could you just leave it out there?" snapped Mrs. Hanson.
"I swore I only turned away for a minute," said Mr. Hanson. Then they heard a crash upstairs. "Oh no, the kids," said Mr. Hanson.
"Great," said Mrs. Hanson, "This is not how I wanted this to happen." She was going to explain to the kids that she was becoming a horse so she could be healthy again and they'll be becoming horses too.
"They're probably panicking now," said Mr. Hanson, "I hoped they didn't knock that jug over."
The two of them headed upstairs. But as they got to the kids' room, they didn't hear kids panicking or even laughing. They heard deep snorts and grunts. Worried, they opened the door and gaped at what they saw.
Six anthro horses, looking to be in their last years of high school at the least, were masturbating furiously. The room was already a wrecked with furniture knocked over and beds broken by incompatible weight. The jug was on its side, a small puddle of milk near its front. The stallions were grunting as they pumped their dicks, which were becoming more than a handful. They were still getting a little taller as their muscles filled out. The mares were moaning as they either rubbing the nipples of their still-swelling breasts or were knuckle-deep in their own pussies.
As the horses had their eyes closed and were really intent on jacking off, they didn't notice Mr. and Mrs. Hanson there. But then Mrs. Hanson yelled, "What are you doing?!" The six horses looked over in surprise. Unfortunately, they had just reached their peak. As such, the stallions' cannons fired their loads straight at the two of them. Similarly, the mares' climaxes caused them to excrete milk, but more velocity than they would have expected. As such, the two humans were splattered with sticky whiteness.
The biggest stallion cleared his throat in embarrassment. "Er, Mom, Dad? It's me, Abraham," he said in a deep adult's voice.
"Yeah, and I'm Faye," said the lightest-colored mare, "And I'm guessing you weren't getting cake."
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"And of course, that caused them to double-dose themselves," said Blythe.
"They were going to do it anyways, but I don't think that's how they would have wanted it," said Damien.
"Well, it could have been worse," said Milly a bit hesitatingly, "They could have seen you..."
"What?" asked Coye.
"Well, I'm kinda wondering how when you were in the thrall of transformation you didn't think about, er, pleasing each other," said Milly. She had definitely been imaging a dick when she had been changing.
"We're siblings," said Faye, "We don't do that with each other."
"Right," said Elijah, "Even animals avoid incest."
"We're not mating each other," said Abraham, "We're looking for other people to have mates with."
Milly had no reason to think they were lying, but a tiny bit of doubt lingered. When she was transforming, she might have accepted any dick she could get. But would she have jumped her own father? That didn't seem likely. She wasn't sure if she'd try it with her brother as she didn't have any brothers...yet anyways. Those events probably did happen as the Hanson sextuplets described. And if anything more than that happened, well, that wasn't Milly's business to ask and she didn't them know them long enough to even try asking.
But that was in the past and certainly wasn't in the present. Milly looked at the six of them. As young as they were chronologically, they were very much adults now. And hopefully they'll have an easier transition than Mary did as they had each other. "So, what have they been teaching you so far?" asked Milly.