A Horrific Experiment Gone Wrong

Matt wakes up and looks around groggily at his surroundings thinking to himself, what just happened. It appears that he was in a stable and was naked on his hands in knees with his dick hanging down from him. He looks to his right and see his twin sister Ally in the same position. This was the first time he had seen her naked in awhile and she was hot with her b cup tits hanging down. The room is dark with many empty stables around. Then the doors to the stable open and sunlight floods the room making Matt have to squint his eyes to see what is happening. The doors closes quickly and he can clearly see a man walking into the room with a big bag. He walks over to his twin sister and him and puts the bag on the bench and starts to talk to them.

"I bet you are wondering why you are here", he says.

His sister and him don't respond.

"You are here because we are doing an experiment and you were chosen because of some certain qualities..."

"But we are only 16", Matt pleads.

The man continues, "This experiment will hurt, I will tell you that, but when it is over we will have created something miraculous."

He then walks over to Matt and says, "We will start with you."

Then he opens his bag and takes out some lube and an assortment of dildos. He puts on a glove and sticks his fingers into the lube.

Matt can see what he is doing and begin to protest but his voice is cut short when he forcefully sticks two of his finger into his ass. The feeling is weird. It is painful and pleasurable at the same time. It is all over quickly though as he retracts his two fingers covered in lube and walks over and takes a 6 inch dildo and walks over and places the tip on Matt's ass.

"If you are going to handle what happens next, we are going to need to loosen you up first", the man says.

He pushes the dildo slowly into his ass before finally bottoming out. The same feeling comes over him as Matt can feel the dildo inside of him. He then takes it back a few inches and starts to thrust it back and forth creating a rhythm. Matt grunts from exertion as he is doing this. Then something really weird happens, he starts to get a boner. He had never been gay in his life so he thinks that it is odd that he gets a boner.

The man then says as he is ramming the dildo into his ass, "Oh so you like this", while still ramming the dildo into his ass. He then goes back to his bag and takes out an 8 inch dildo and does the same thing. The 8 inch dildo makes Matt feels fuller then the 6 inch dildo. As he is ramming the dildo in he can start to feel his ass getting looser and looser.

After about five minutes of the man ramming the dildo in his ass the man says to him, "You are almost ready, there is just one more thing I have to do to you to get you ready for the main event, I have to clean you from the inside out. "


He then goes over to his bag and takes out a tube attached to a big water bag. He goes over to a hose on the wall and fills the water bag full of water. The bag must have been big enough to hold a gallon. Then he takes the bag and hangs it on a hook above him that Matt had not noticed before. Matt think he recognizes the bag from some of the porn he watched. It was an enema, he thought to himself. He then takes the tube and proceeds to stick it right into his already loosened ass.

"I am going to need you to be really clean in there if my experiment is going to work", the man says.
He then turns a valve and the water starts to flow into his ass. Matt can feel the cold water flow into his ass making it expand. After a minute he can feel his belly start to expand and he looks back and his belly looks like he is pregnant. Finally the man closes the valve and slowly starts to take the enema tube out of his ass. As soon as he does this, some brown fluid shoots out of his ass and onto the floor. It feels really weird having the liquid shoot out of Matt's ass. He then proceeds to put the enema tube back in

Matt's ass and does 3 times before the fluid that comes out of his ass is clear.

The man then pulls out walkie-talkie and says into it, "He is ready, bring him in."

Matt turns around and sees the doors to the barn open and a man walks in directing a stallion behind him. "Oh no", Matt thinks to himself, "this can't be."

The man then walks over to the stallion and starts to rub it cock. Before long a 2 foot long cock springs out from the horse.

Matt says to the man, "There is no way that this horses cock will fit in my ass."

"Well it has to", the man says.

The man then presses a button on his remote and the straps holding his hands and legs to the ground tighten and he is lifted up into the air on a platform that he was on that he had not noticed before. The platform stops at the perfect height for the horse to penetrate his ass. The stallion then rears up and places both its hooves on a bar so that the hooves will not be on Matt. Then the stallion starts to thrust searching for his hole. Matt starts to prepare himself for the inevitable. Finally after four or five missed thrusts, the horse finds his hole. At first the horse can only fit the apple sized tip of his dick into his ass. The horse then begins to thrust his dick further and further into his ass. Finally, after a couple of minutes of the horse going deeper and deeper into his ass the horse bottoms out and stands still for a couple of seconds. The pain is excruciating. Matt almost blacks out from having the horse dick so far up his ass. Then the horse pulls out six inches and thrusts. He repeats this action and then forms a constant rhythm. The pain begins to subside and the pleasure kicks in. Before long he can feel his own dick start to shoot off on the floor. Then after ten minutes of straight fucking from the horse, he can feel the horse's balls tense up. The horse then bottoms out and his dick erupts with cum. The hot fluid feels so good inside his virgin ass. The ropes of cum cover the inside of his ass and begins to make his ass expand. The horse keeps cumming for about a minute. Finally the horse stops and right as the horse pulls its dick out of him the man puts a but plug in.

"Now we don't need to waste any of that cum do we", the man says.



He then lowers the platform and takes the straps off Matt's legs and hands and he collapses on the ground. He feels so bloated and he looks at his stomach and it looks like he is pregnant from all the cum inside of him. He can feel it swishing around in his ass and it feels kind of good. Then he passes out on the floor....

Matt wakes up on the cold ground naked and looks at himself. His stomach bulged with all the cum inside of him and his ass ached and Matt tries to stand up but cannot. He looks around and saw that he is in a horses stable. He then turns and looks at his twin sister lying next to him naked. She too had a stomach that bulged like she was pregnant too but she still looked sexy. Matt could see her B-cup tits because she was lying on her back and her beautiful pussy with just a little tuft of hair at the top of her slit. His cock starts to grow but at that same moment she woke up.

"What happened", proclaims Ally.

"I don't know, says Matt, "we were going to summer camp and then..."

Matt looks over at Ally and says, "Did the horse..."

"Fuck my pussy, says Ally, "Yeah"

Matt then hears the doors to the barn open and eyes the man as he walks into their stable.

"Rise and shine boys and girls", the man says, "I bet you have been wondering what the experiment I
preformed on you was for. I didn't want to tell you yesterday to spoil the surprise but here we go. Those 2 horses yesterday that you had a little fun with, were normal. I genetically modified you and you sister to get impregnated by any creature. I also modified the time the pregnancy will take to make it go from 9 months to 1 month so you will feel changes pretty soon. Another thing is that the reason I plugged up your holes from letting the cum seep out was because the creatures cum takes about 4 hours to impregnate you. The reason I wanted to do this was because I wanted to create the greatest horse ever. I could not do this with mating 2 horses together but I had to mate a horse with a human because with a human, the horse can be very intelligent. The reason I picked you 2 was because you both have high IQ's, are athletic and it looked like you could handle this. And I thought it would be fun to have a brother and sister. Oh, and by the way, my name is Dr. Jekyll Any questions?"

Matt speaks up, "You cannot be serious, there is no way that I can be... pregnant."

"Oh, I am quite serious", Dr. Jekyll says, "I have given you, ah I don't want to get into specifics. Any more questions?"

"Yeah", Ally says, "How will the foal come out of our..."

"Well your bodies will be changing to accommodate the foals but it will still hurt very much", Dr. Jekyll
says," It will probably hurt more than a normal pregnancy so be prepared. You will stay here in this stable for the remainder of this pregnancy. Oh, and one more thing."

Dr. Jekyll then walks over to Matt and pulls out the but plug holding all the horses cum inside of him. The cum shoots out of his ass and all over the concrete floor of the stable. He then pulls the plug out of
Ally and says, "Well I hope that this semen did its thing."

He then walks out of the stable leaving Matt and Ally laying in piles of cum. They both sighed out of
relief when the cum was finally out of their pussies and asses.

"What are we going to do now", exclaims Ally.

"I don't know", says Matt.

Matt then lays on the ground in his pool of cum, thinking about the events that happened yesterday. Then the man walks into the stable and says, "Here's dinner."

Then he walks out of the room. Matt crawls over and gets the 2 buckets and brings them over to Ally.
Ally gives Matt a puzzled look and he just shrugs it off. He then takes a handful of the grain and puts eats it. "It's not that bad", says Matt.

"Yeah right", says Ally

She then tries the grain and agrees with Matt. They could have probably eaten anything at the moment.
They had not eaten anything in awhile and they were both very hungry. They then took turns sipping water from the bucket until the bucket was drained. They then fall asleep on the cold concrete.

Matt wakes up first the next morning and feels different. He feels a weight on his chest and looks down and sees that he has some A-Cup tits. His hips had widened too and his stomach was a little bloated. His ass also did not feel sore anymore. He looks over and sees his sister awake as well. He could see that she also had changes. Her hips had widened and her tits went from an A to a B-cup. He then hears a giggle come from his sister.

"What's so funny", Matt says to Ally.

"Nothing", Ally says, "That was quite the experience we had yesterday."

"Yeah", Matt says, "It hurt at first but after awhile it felt really good."

"Yeah", Ally says, "The horses big dick felt so good in my pussy. The best part was when he cummed, it
was so great that it gave me the best orgasm I had ever had."

"Are those real?" Ally says pointing to her brothers tits.

"Yeah, unfortunately they are. I think that this is one of the side effects." Matt says, "Feel them if you do not believe me."

She then walks over to Matt and places her hands on his tits. Matt was shaking in anticipation for this and lets out a small moan as she places her hands on his tits and starts to feel around. Ally then said to him, "You can feel my tits if you want."

Matt then places his hands on his sisters B-Cup tits. Ally too lets out a small moan as he does this. Ally's tits felt so good in his hands. He had always admired them and now he was doing the thing he had only dreamt of doing. Her tits were the perfect size and they were still firm. Matt then wanted to take it a little further. He takes one hand off her tit and started to move it down her body. He reaches her clit and starts to rub it.

Her body shook violently as the orgasm went through her whole body. After the orgasm was over, she said to her brother, "Now your turn."

She then grabbed his already hard cock and put it into her mouth. She started to suck his cock and massaging his balls at the same time. Matt could feel his sister sucking on his cock, licking the tip every once in awhile. Then he could feel his balls tense up and he said to Ally, I am going to cum." Matt could then feel Ally start to deep throat his cock. Matt then erupted with cum and then shot it all down his sisters throat.

Matt then took his cock out of his sisters throat and picked her up and laid her in a corner on the hay. He then took his 8 inch cock and directed it into her awaiting pussy. He pushed in slowly not wanting to hurt his sister. Finally after a little of pushing, he could feel his balls rub up against her ass.

"Are you ready", asks Matt.

"Give it to me", replies Ally.

Matt then pulls out and slams into his sister. He then started a rhythm and he could feel the precum dripping out. His cock feels so good with his sisters pussy enveloping it. After what seems like an eternity, Matt can feel his balls tense up and he goes hilt deep and cums into his sister as hard as he can.

They both lay there for a few moments with Matt's dick still in his sisters pussy and that's when they heard someone clapping.

Dr. Jekyll had been watching the whole thing and was astonished. He had never thought that this would happen. He then said, "Bravo you two. That was quite the show."

Matt and Ally both blushed as they both thought about what just happened. What made it even worse was that someone had seen them do it. Matt then pulled his semi hard dick out of his sisters pussy and a little stream of cum followed after that.

After a few awkward seconds, the Dr. Jekyll says, "Well the reason I came here was because I needed to feed your kids", pointing towards there bulging stomachs, "The best way to do that is by the semen from their fathers."

He then leads the two of them out of a stall and into another stall where both their horses were kept.
The black one was Ally's and the brown one was Matt's. "Well, I will leave you two to get to it", Dr. Jekyll says as he backs out of the room.

They both stand there for a few minutes when Ally says, "Well I will go first to show you how it is done."

Matt watches as his sister takes the huge horse cock and sticks it in her mouth and starts to suck on it. Matt then watched as she took her hands and started to jack off the horses massive dick. Soon he can see the horses balls tense up and he knew what was going to happen. He could see her struggling to swallow the massive amounts of cum from the horses but soon he could see that she couldn't take it any more so she pulled the horses cock out of his mouth as it was still cumming and it cummed all over her petite body. This turned Matt on very much and soon he had a big boner watching the horse cum all over his sister.

Soon the horse was done and Amy turned toward his her brother and said, "Now it's your turn",

Matt had not been thinking about what was about to happen. He walks over to his brown horse and starts to rub its cock. Soon the cock is at full length and Matt just stares at it.

"I don't think I can do this", he says to Ally.

"Yes, you can, just do what I did", Ally says encouragingly.

Matt then takes the whole cock and puts it into his mouth. He starts to suck on it at the same time jacking off the horse with his hands. Matt loves sucking the horses cock. He can taste the precum oozing from the horses slit and he loves it. Soon the horses balls tense up and send ropes of cum down Matt's throat. Before long Matt's stomach is full and he pulls out the cock from his mouth. The horses dick then starts to shoot cum all over Matt's body covering him from head to toe.

Dr. Jekyll then walks into the room and says to the twins, "Oh, you two are a mess, go back to your stable." Matt and Ally comply and follow them back to their stable. He then puts a bucket of cold water and a horse brush and says to them, "You two should probably clean up."

They then grab the bucket and begin to scrub each other with it focusing on the "sensitive" areas mostly. This routine goes on everyday for a couple of weeks. They wake up, have sex, get covered in cum, and then wash each other. Their bodies go through many more changes as well. Both of their hips get wide enough to accommodate the horse. There tits swell up in size too. They go all the way to the D-Cup and stop. Their stomachs keep expanding rapidly in size too. With about a week left, it looks like they are both having quadruplets in their stomachs. They have to stop having sex because their bellies are so big but they can still feel each other up.

Then one day, Dr. Jekyll walks in the room with a box full of dildos. He says to the twins, "Here, these are for Matt. If you want to deliver this horse without any damage then you will need to work on making your rectum big enough to accommodate this horse."

"What about me?", says Ally.

"You should be fine, women are meant to give birth and I think that your vagina will do just fine."

The man leaves and Matt goes over and looks at the dildos. They are not that long but some of the girths of the dildos were huge.

"Want to help", Matt say to Ally.

"Sure", Ally says, "Now get into the position."

Matt gets on his hands and knees and Ally chooses the smallest dildos and penetrates Matt's ass slowly. Matt moans because he had been craving having the horses dick in his ass for awhile but he knew that it would hurt the foal. She then worked her way up to the biggest dildo which was as wide as the horses dick. She did this every day until one day Matt had some sharp pains in his stomach and soon after his sister did too.

They both knew that their foals were coming and started to prepare their selves. Out of instinct, they both lay on their sides because that is how horses normally give birth. They both yelled as they went through the first contraction.

Dr. Jekyll then came running in and says, "The show has just begun", and brings a chair over to watch the festivities. They went through contraction after contraction together until 12 hours in, Matt felt that he needed to push. He started to push and could feel the horse sliding down his colon. He pushed and pushed until he looked back and could see the head out. "Almost there", Matt thought. The pain was excruciating. He kept pushing and pushing until the front legs popped out, then the back legs popped out after and he was done. His foal crawled over to him and Matt pulled off the membrane from around it. The horse then started to suck on Matt's tit. The feeling was amazing as he could feel the milk leaving his body and into his horse.

"Nice job Matt", Dr. Jekyll says, "That is a beauty."

Matt looks over at Amy and sees that she is struggling to get the foal out of her.

"You are doing well", Matt says encouragingly, "Almost there."

Matt can see the head start to come out of his sisters pussy. Ally keeps pushing and soon the front legs pop out and finally the back legs. Ally sighs as her foal finally comes out. The two twins then fall asleep with their babies sucking on their tits.

They wake up the next day and they both feel different. Their bodies had gone back to normal. Matt no longer had tits and widened hips and Ally tits and hips had gone done in size as well. They were perplexed. Then they could hear the barn doors open and in walked Dr. Jekyll into their stall.

"Hello", Dr. Jekyll says to the twins, "You two did a nice job yesterday."

He looked at their perplexed looks and says, "There was one more thing that I did not tell you about when I modified your bodies. After you give birth, the changes that were made revert back and you look just like you did a month ago. Unless you want to keep the changes."

"No, no", says the twins in unison.

"Ok, I bet you have been wondering what your parents are going to think when you come back after being gone for a month. Well, when I kidnapped you, your parents were going to send you to camp for a month and I have been sending them letters about all the fun you have been having. Do not tell anyone about what happened today unless you want me to release a video documenting what happened. From you having sex with each other, with a horse, and giving birth. Are we clear?"

They both nod in agreement. He then tosses in some clothes and tells them to get dressed

Matt had gotten so used to be naked all the time that the clothes feel weird. They then look at each other and Matt knows that life will never be the same.