The Horse Experiment –Revised– by flosiedon

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.