Twilight locked her door. It was four o’clock on a Thursday, nopony was going to need her downstairs in the library. Spike was out playing with the Crusaders. It was a nice moment she had all to herself. She stuck her head out a window and just breathed the fresh air, relaxing as it filled her lungs.
She made a quick trip to the bathroom. Then, relaxed and refreshed, she lay down on her bed.
The blankets were cool and soft under her. She flicked her tail away from her rump, lit her horn up, and gently stretched her anus open. Such were the advantages of being a unicorn. It was just a centimeter to start. She liked to slowly ease herself into these sensations. One and a half centimeters.
She paid close attention to her body. It was fascinating if you took the time to watch the arousal unfolding. What she called heat, pressure, need when she was in the throes of horniness had their origins plain in this still clear minded state. Blood flow increased in and around her sex organs. Glands awakened. The muscles around her vaginal canal relaxed, allowing the space to expand. Her heart rate picked up to supply that extra blood, and accordingly so did her breathing.
All this came back up her brainstem and into her mind. The data in summary: she was a physically healthy mare ready for coitus. She considered how she was a young mare too, in the prime of her fertility. She was alone, of course, and even if she had a partner, she would have had no intention of becoming pregnant. But that was what all this was for, after all.
She stretched to two centimeters. Her sexual instincts seemed as if they were separate from her self; they spoke to an imaginary stallion with impatience “Penetrate my vagina, anytime you’re ready.” Memories of orgasms past were a chorus reminding her how good it would feel to touch her clitoris.
Those very same memories also gave her the restraint to hold off on that. She conjured to mind fantasies of a stallion cradling her. He was almost Big Mac. She didn’t know that she’d date him, but he was quite the stud. Him being Applejack’s brother made it feel weird to contemplate. She could say to herself that she’d like him to rut her, but questions about what that would do to her friendship with AJ always distracted her when she tried to masturbate to thoughts of him.
The stallion in her mind was like him, tall, and strong, and gentle, and quiet. But he was more often a unicorn or pegasus. He had a gold coat. She thought that would go well with her own colors. And his cohorts were gleaming in purple and gold. He nipped at her rump as he joined her on the bed, embraced her, pulling her up against him. She giggled girlishly as he tugged at her mane and nibbled her ears.
That was all imaginary. She pushed her magic further, actually simulating a penis pressing into her anus. She began to stretch herself more steadily, she went to three centimeters of opening and kept going. She also let the magical pressure expand inward from the sphincter into her rectum. Four centimeters.
Someday, she would work up the courage go out and buy a physical toy to insert. She knew where the shop was, and her eye lingered on the door every time she walked by. But what if somepony saw her going in? What if she met somepony she knew inside?
The diameter of her anus was five centimeters now. It had taken practice to comfortably achieve this. Average ponies did not do this to themselves, she knew. It was harmless, as deviancies went, but it was deviant, something to keep to herself and not involve anypony else.
Her fantastical coltfriend held a flashlight. He could look right inside her and inspect her colon. Now that was opening up to somepony he would joke.
Someday she would have a real coltfriend. Would he be awed, enthusiastic? Would he fill the void in her body with his own body? Or would he just be disgusted?
Her fantasy said “More! Wider!” She trembled lightly. She bit her lip as she reached six centimeters. Organs are not isolated. Her actions were focused on her anus and rectum, but that kind of stretching put no small amount of pressure on the top wall of her vagina. It was a good pressure. Her nerves were not meant to distinguish precisely where things were in there. The result was a sense of fullness in both cavities.
She clenched and unclenched her vagina. It was well lubricated by this point, and the slick feeling of the movement was wonderful.
The single static source of pressure she had been applying so far had a nice elegance to it, but it took a long time to make her cum. She did not have the patience for that today. The solution, as with most things, was more magic.
She added two little dots of telekinetic press. One on her clitoris, right at the bottom where it joined her vulva, the other inside, on her G-spot.
She buried her face in the blankets and grabbed a mouthful of them. Even with nopony around, there was a quality to desperately muffled screams and moans that open ones lacked. Perhaps the attempt to hide the sounds created a feeling of vulnerability or transgression. Maybe it was the excitement of sending herself into throes of passion so strong that they could only be physically, not willfully, restrained.
Whatever the case, the magnitude of pleasure had a highly nonlinear proportion to the light flutters of magic she applied to herself. She wondered sometimes why her body was like this. It was probably unanswerable, but whatever reason had given her the ability to feel and experience these things, she was thankful for it.
Twilight Sparkle orgasmed. Her vagina began clenching again, as did the rest of her pelvic muscles. But this time the contractions were involuntary. Her anus generated an intense pulsating as it tried to squeeze the immovable field of magic holding it open.
She bit the sheets harder. Her mind was awash in a sea of endorphins. She savored the glowing pleasure. As it began to taper off and the heightened sensitivity of her genitals faded, she resumed her stimulation. It was more aggressive, and in her state of arousal, she lit off another orgasm within a minute. This time it was accompanied by ejaculation, a spurt of fluid that leaked out of her onto her thighs and dribbled down to the bed.
Twilight panted through her nose. She felt half melted. She debated going for a third orgasm, but the sweet spot for it passed. There was only a narrow window of time for chaining them. Oh well. She enjoyed a nice masturbation session very much, but it was a fine spring day, and she didn’t want to spend all of it playing with herself. Bright light beckoned through the windows.
That would have to wait for a little bit. She slowly began to allow her anus to relax, wincing at the soreness she’d won for herself. It was going to take at least twenty minutes to get enough muscle tone back to be confident of avoiding any accidents. But that was just the price she paid for her fun.
She went to the bathroom and urinated and wiped herself off. Then she stripped the sheets off the bed. It was laundry day anyway.
