The Twilight Experiment

Princess Twilight looked to the mirror, seeing the modifications done to it. There were crystals placed nearby the machine she used to keep the rift between the two worlds open. The alicorn hoped that they'd serve their purpose in this experiment. She sat down, and looked over the notes, making sure they matched what she did. With a relieved sigh she looked up to the mirror, waiting a moment for her counterpart to finally finish her part.

At last, not too soon after, a familiar purple-skinned girl accidentally tumbled through the portal. She groaned lightly, not expecting such a trip. "I'm okay..." she assured. Twilight stumbled back to her toes as fast as she could. This time she wore a lab coat, which was buttoned up and her hair was already down, not in its usual bun. "Okay... I-It looks like it works."

Smiling at her doppelganger, Princess Twilight raised a hoof, "I'm rather surprised it did. The fact we can keep our forms like this is quite a feat. But this should only be a temporary thing. It'd be easier if we kept our transformed states."

Twilight nodded in agreement, "I agree." her eyes kept gazing to another direction. The princess knew where and her mouth formed 'oh' once she followed where her eyes went.

"You... Want to... get started already?" Princess Twilight wondered curiously.

"Kind of." admitted Twilight with a light blush. She took off her glasses, reaching for the nightstand.

Once they were back in the bedroom, the alicorn took the time to close off the windows and blinds, giving the two counterparts privacy. "Okay..." exhaled the princess. "We should be clear again. I guess we can," she inhaled, "Begin the final part of this experiment. This one is an unknown anamoly though."

The two Twilights sat each other down on the bed. The human Twilight removed her lab coat, revealing her bra and she removed her skirt, dropping it onto the ground with the white coat. She was unsure of how to continue the action. Unsure, she placed her palms on the alicorn's shoulders.

Princess Twilight whispered into her doppelganger's ear, "Do what you want. It will be fine. We're doing this to test the waters, remember?" she reminded her.

Hearing the assuring words of the pony, Twilight reached her hands to the straps on her bra and unstrapped them, allowing that to fall on the pile as well. She admitted, that she was getting a little excited, yet nervousness played a part in her emotions.

'I'm a human performing coitus with a pony that is me.' the girl thought, 'I-I can't mess this up.'

Placing her doubts aside, Twilight kissed Princess Twilight. The sensation felt different this time. The girl could still feel the fur on her double's lips, but the alicorn could feel the softness of the human's own. It was a unique feeling for them to say the least. Princess Twilight leaned deeper into the kiss, parting for a second to lick her counterpart's lips before moving back in.

Twilight tilted her head and rubbed a hand down the pony's mane, pushing her forward so they were lying down. The girl pressed her hand onto her doppelganger's chest as she felt the princess' tongue move in tandem with her own.

Alas, they separated as they held one another close. Twilight and Princess Twilight gave each other a wide eyed stare, unaware of how deep they were into the moment. Twilight's arms wrapped around the mare's neck.

"So... That's what it feels like." muttered Princess Twilight, holding a hoof to her lips.

Twilight closed her eyes, "D-Did I ruin it?"

"N-No, it's just... Huh." Princess Twilight murmured. She placed her hooves on the human's chest and held them firmly, earning a loud squak from her counterpart. Twilight reached for her muzzle and planted a deep kiss.

Any excuse they had to continue was gone, now lust replaced those curious emotions, wishing to move on anyhow. Twilight moaned, feeling her doppelganger's hooves push on her breasts, giving her a sensual feeling unlike anything before. Her hooves were soft, yet rough in their movements.

Twilight straddled herself and moaned as they continued making out. Princess Twilight lightly flicked her tongue as they moved, dancing around the human's own wet appendage. The girl reached her hands to the princess' shoulders, holding her close.

Deciding to continue the experiment, Twilight gently moved her hands to Princess Twilight's wings and lightly stroked a finger on her feathers. Instantly, the alicorn's wings unfurled as they separated their lips, the human continuing to lightly rub her fingers on the tip, causing the mare to moan in pleasure.

Now excited, Princess Twilight said no words as she moved her hooves around Twilight's breasts, caressing them as lightly as she could. Loving the alicorn's touch, Twilight smiled at the feeling and her eyes nearly rolled to the back of her head in pleasure, feeling the mare's hooves lightly rub her nipples and areola.

Twilight continued to play with the princess' wings as Princess Twilight moved her head forward, bringing her mouth onto the human's chest, sucking on her nipple slightly. The girl had to stop for a moment to process what was happening, but she didn't want it to end. "O-Oh..." she moaned in a hushed tone.

With a soft popping sound, Princess Twilight moved her head back, a satisfied grin and drool running down her mouth seen. She licked her lips, reaching for the girl's mouth again. Twilight reciprocated the action and continued caressing the mare's wings with her fingers. Her hands unconsciously slid down the pony's curves and found her flank, around the cutie mark, which she rubbed in a circular motion. Princess Twilight was heard moaning, never stopping the kiss.

Using her magic, Princess Twilight lowered her doppelganger's panties, not breaking the kiss in the process and she got a good look at her lower lips before closing her eyes again. The two leaned around, to where the alicorn lay atop the human.

Princess Twilight stopped the kiss, her human counterpart wondering what she was doing. She saw the alicorn lower her head in between her legs. Something sparked within the girl, feeling her pony counterpart's tongue down there. Every movement sparked a volt of adrenaline in her. Princess Twilight moved her head in a little more, reaching her tongue into the girl's vulva, tasting her cum with each precise movement.

The girl loved every moment. Everywhere her counterpart licked, she was about ready to melt. Who knew that her pony self could make this feel so good? That was why they had the experiment in the first place.

Twilight could barely contain herself as Princess Twilight raised her head and moved it so she was staring lovingly into her double's eyes, feeling her cum leak down onto the bed once she was finished, leaving a small stain. But that didn't matter to them. "H-How was that?" the princess asked, wiping a hoof on her muzzle, removing anything that drooled from her mouth.

Leaning forward, Twilight gave her doppelganger a deep kiss. As they separated, the girl gave the mare a few extra pecks, showing that she wanted more, but she wanted to answer her counterpart.

"Wonderful..." Twilight let out in a squeaky tone. She playfully shoved her doppelganger and with a giggle, wrapped her arms around the pony again, feeling Princess Twilight stroke a hoof down her long hair. The girl was once again lying over the mare, who didn't mind the change.

Twilight pecked Princess Twilight's face, planting her lips on the pony's own for a second before leaning toward her neck. The girl began to softly kiss her double's neck, almost sucking on it. Her hands started to stroke the alicorn's chest, playing with some of the fur hairs. She felt weird at first doing this, but she found the skin and bit a small tuft of fur, ticking the pony and making her giggle lightly as she melted into the embrace.

The girl brought her head up and had an idea. The princess didn't mind kissing her counterpart again. But she was a little confused, feeling a hand grip her horn. She felt her doppelganger's hand rubbing it in an up and down motion. This sent shivers down the alicorn's spine, not used to the sensual feeling on her horn.

Suddenly, sparks of magic bursted out of her horn, which prompted the girl to stop. In excitement, the princess deepened the kiss and moved her tongue down, licking the girl's mouth as they parted, saliva seen dripping from their mouths. They wiped their lips clean and gazed at each other. The two of them were panting, no doubt from the brief moments of adrenaline wearing them down with each precise moment of pleasure. They were unused to this. Princess Twilight was obviously curious, "H-How did you..."

"I-It looks like..." Twilight stammered, her face turning red. The mare's face did as well, knowing what she was referring to and she put a hoof to the girl's mouth,

"Oh." was all the princess said. She felt wet and noticed the musky smell again, this time coming from her. But she had no energy to continue. "S-Should we wrap up for tonight?"

Twilight nodded, "Yeah. This was... fun." a smile formed on her lips. "We learned a lot about our anatomy."

The alicorn agreed and kissed her double on her lips, "And ourselves. We'll record everything in the journal after a small nap. After changing the portal and that, I think we could use a moment to rest."

The girl nodded, moving so that she was on her back. Princess Twilight smiled, moving the two of them under the covers with her magic, wanting to rest. The alicorn leaned on Twilight's chest and she wrapped her arms around the pony's barrel, giving her a soft peck on the forehead. The human looked back and knew there was one matter to attend to.

A certain dark doppelganger in her head.