Author's Note

FAIR WARNING: Dr. Twilight Sparkle intimately checks Shining's sperm count.
If that sort of thing isn't for you, go ahead and skip this chapter.
(You won't miss anything important. And the pairing doesn't return in the rest of this story.)

The Appointment (Cloptional)

That afternoon, after train ride south, Shining Armor sat nervously in the Canterlot Clinic waiting room. He had made a general appointment, without specifying what it was he was being seen for that evening. Being a prince now, he had to be wary of the rumor mill concerning juicy gossip about celebrities. And the prince being tested for infertility was about as scandalous as it got, short of having an affair.

"Mr. Armor?" the receptionist nurse asked into the room. He stood up and walked over to her. "This way." He followed her down the hallway to the examination room, directing him inside. "Please have a seat on the table. The attending nurse will be along shortly, along with the doctor," she said before closing the door and returning to her position at the front desk.

It was late in the evening. But he insisted on scheduling the appointment that day, as soon as possible. Like removing a bandage, he wanted this to be over with as soon as possible. A quick knock at the door before it opened and the nurse stepped inside, her bangs hid her eyes, looking down and reading her clipboard.

"Good evening. So what brings you in this evening Mister..." She adjusted her glasses as her eyes ran over the form, seeking the patient's name. "Armor!?" Her head snapped up. "Shining!?"

"Twilight!? What are you doing here?" He asked.

"I got bored in my Crystal Tree Castle, so I decided to go out for my doctorate degree. I'm doing my requisite clinic hours," she explained, showing him her badge on her white lab coat. "Why are you here?" she asked. He blushed, running his hoof through his mane.

"It's- um, medical," he said. Twilight blinked at him.

"Wow. How do you not already have your doctorate?" she asked with sarcasm thick enough to sink into a pool of mercury.

"It- it's personal. It's... embarrassing," he said. Twilight rolled her eyes. It was not the first time she'd heard this from a patient.

"Okay. Alright. What did you get stuck in your butt?" she asked.

"What!?"

"Did you get something lodged in your rectum that you can't get out?"

"What!? NO!" he shouted.

"Okay, okay. I just figured I'd go with the common reason first," she said.

"Common!? How often does somepony come in here with THAT problem?" he asked in disbelief. Twilight's eyes just sort of drifted off, staring off into nothing, a thousand yards away. Her memory flashed back every time she'd had to go 'spelunking' for some hapless pony that had gotten too ambitious with their back-door behavior. Every sphincter, seared into her memory.

the horror... the horror

Twilight shook her head after a long, silent moment, returning to the present moment.

"That's confidential," she said at last. "As is anything you tell me inside this room, unless you are planning to harm yourself or another, then I am required by Equestrian law to intervene. Are you planning on harming yourself or another?"

"No."

"Okay. Then you can tell doctor and I anything and we are beholden by law to keep that information in this room." She nudged him with her elbow. "Don't worry, your secret is safe with me," she teased. It did not improve his mood.

"You would be on the list of ponies that I don't want to have find out about this," he said. "Can't I just talk to the doctor?"

"Shining, the doctor is very busy. You need to tell me what the problem is so we're not wasting his time. He's not going to bother if you just have a sliver that I could just as easily remove. That's why I'm here, the entire purpose of this job." She looked at the clock, approaching the end of the hour. "Look, you're my last patient of the day and then I can log my hours and leave. I want my doctorate, Shining! Don't screw this up for me!" She gave him that glare that told him she was serious. "I've seen countless thing lodged in rectums, every sexually transmitted infection you can think of, thrush and ass-rot. There is nothing that you can tell me, nothing left at all, that is going to shock me."

"Thrush?"

"It's a yeast infection... in your mouth," she explained.

"Ugh!" He recoiled. "I don't even want to know what ass-rot is!"

"Imagine somepony going through their entire life without ever having been taught how to properly wipe."

"I- I don't want to imagine that."

"So what is it that is so embarrassing that you don't want to tell me?" she asked. His eyes darted back and forth for a moment. He took a deep breath and steeled himself to answer.

"I- we, Cadance and I have been trying to have a foal. It's been difficult. And I came in to see if it's because of me," he admitted. Twilight's demeanor returned to, and remained, professional. She held a pen to the forms on the clip board, jotting some notes.

"Are you having erectile difficulties?" she asked, keeping her tone perfectly neutral. She asked the question as plainly to her brother as though she were asking what flavor of ice cream he preferred. She took his shocked silence for confusion. She looked up at him, elaborating, "Are you having erectile difficulties?" she repeated, "Are you able to achieve an erection?" she asked.

"No! I mean, yes! I mean, IT works, I can... achieve erection," he half mumbled. Twilight doubted very much that he could, with whatever blood he had left, that wasn't rushing to his red cheeks.

"Are you able to achieve vaginal penetration?" she asked.

"I- we uh, I uh, I-"

"Yes or no will do," she said, trying to help.

"Yes," he said quickly.

"Are you able to achieve orgasm?"

"Y- Yes," he said. Twilight jotted a few more notes.

"Are you able to bring your partner to orgasm?" she asked.

"What? What does that even have to do with-" Twilight cut him off.

"Studies have consistently shown uterine contractions during orgasm may help propel sperm into the cervix. And the flood of oxytocin during orgasm definitely makes her more relaxed. And that means you've already cleared the biggest baby-making blocker: stress. A mare that orgasms during intercourse is approximately thirty five percent more likely to conceive."

"Oh."

"So, are you able to bring your partner to orgasm during intercourse?" she asked again.

"Yes," he answered. He couldn't help but smile a little, proud of the fact.

"How many times per session?" she asked. He gave her a bit of a sideways look. "I'm just asking the standard questions to narrow down the root cause of the problem. How many times per session?"

"Uh..."

"On average."

"Five or six? I guess," he said, somewhat unsure. It could have been more. He lost track sometimes. Twilight arched an eyebrow slightly.

"Lucky gal..." she penned a few more notes. Shining's grin widened. Twilight flipped over the page to another section, filling it out. She opened a drawer of the cabinet and retrieved a large liter cup with measurement lines on the side. "Well then, all that's left is a sample for the lab, and we can get a count for you." He blinked at her. She passed the cup to him. He took it, looked at it and looked back at her, unable to fully register what she was implying. "A sperm count?" she said, pointing at the cup. His mouth hung slightly ajar. "From a sperm sample. From you."

"Uh..."

"I know you're familiar with the mechanics of it. I used to wash your sheets, you know. Now hurry up," she said, taking a seat in a chair in the far corner of the room. She took out a crossword puzzle to busy herself with while she waited for him to 'produce'.

"Uh, Twilie, do you have to sit in here for this?" She looked up from her puzzle.

"Oh, don't worry about me. I deal with this stuff all the time. It's nothing I haven't seen before. We used to take baths together, remember?"

"That's not what I mean. I uh, you being here is- it's a little 'distracting'."

"Oh, did you need something to stimulate yourself? I think we have some Playcolt magazines in here somewhere." She looked through the bottom shelf of the cabinet for some 'inspirational material' as they called it around the office. In the small space, she couldn't help but to have her backside directed at him. She rifled through the cabinet for a few moments. "Well, we don't have any magazines or mare extract," she said. "You can look at mine I suppose." She hiked up her lab coat and flagged her tail, flashing him a view of her marehood and wafting her scent toward him with her tail. He crossed his hooves in front of his eyes.

"Twilie! No! You're my sister!" he said.

"Not right now, I'm not! I'm Head-Nurse-soon-to-be-Doctor Sparkle. And you are my patient. And that's it," she said with authority. She leaned on the counter and returned to working on her crossword puzzle. All the while, presenting herself to her ~~brother~~ patient. "Now you can look and smell all you want. I'm not going to judge you. But when I finish this puzzle and turn around, there had better be a sample in that cup." She glanced backwards. He was still just sitting there, trying to look anywhere but at her displayed privates. "I would hurry if I were you. You know how good I am at crosswords." She went back to her puzzle, filling in the squares with her pen. That's right. She didn't use at pencil. She used a pen when doing crosswords. Yeah. She was that good.

"Twi-"

"It's Nurse Sparkle to you. And I don't hear any clopping back there..." she said sternly, flicking her tail again. In the small room, he couldn't help but smell her scent. He had smelled it before, living in the same house as her. But it was always diffuse. Here, and now, it was directed. She was purposely having him smell her scent. And it was eliciting an involuntary biological response that he was not particularly proud of at the moment. He chewed his lip, wrestling with the conflicting spectrum of emotions he was feeling; from arousal, to the disgust thereof. The prior becoming physically evident. In the reflection of the metal cabinet door, Twilight caught a glimpse of his emerging shaft. "Ah, there we go. Now just run your hoof up and down along its-"

"I know how to do it!" Shining huffed. Twilight smirked to herself and returned to the puzzle, trying to politely not watch, despite the show she was freely giving him. Shining sighed and resigned to the weirdness of the situation. 'Fuck it,' he mentally gave it, putting his hoof on his shaft, growing to full mast as he began clopping away. He looked up at Twilight's winking marehood. 'Just don't think of her as your sister. It's just some random hot nurse...' he thought. Twilight briefly glanced up into the metal reflection again, getting an eye for his length and thickness.

'Lucky gal indeed,' she thought to herself, envious that Cadance got to be on the receiving end of that beast. She tried to push the thought from her mind. She tried to focus on her puzzle. 'A ten letter adjective for inter-familial sexual activity.' She glanced up at her brother in the reflection again, his nostrils flared as he stroked his shaft while he stared at her wet, winking pussy. "I'm almost finished. You had better be, too." She looked back down and filled in the last space in the crossword. Incestuous She put her pen down, loudly. "Time's up."

"Uh! I- I uh!" Shining stammered. Twilight watched his eyes follow her pussy as she slowly turned back to face him.

"Do you need... help?" she asked, pulling on a couple latex hoof-gloves. Before he even had time to answer, her gloved hooves were on his shaft, stroking him smoothly with the lubrication his pre-cum was providing.

"Twi!"

Nurse," she corrected him. He winced and struggled to speak.

"Nurse!"

"Yes?"

"Stop! I- It- I- That-"

"I told you, don't think of me like that," she said.

"It- it's not that-" he stammered. She paused. He gasped for breath and pushed her hooves away. "I, I haven't had to 'take care' of myself for a long time. Especially now that we've started trying to have a foal. We... try every chance I get. And..."

"And what?"

"And I've... IT has gotten a little spoiled. Hooves just don't do it for me anymore," he said. She gave him a stern look.

"I am not putting that in my mouth," she said. Shining gasped, apologizing.

"I'm sorry! I didn't mean to suggest-"

"Saliva is very bad for a sperm, it kills them, throwing off the count," she explained. She turned around, locked the door, and knelt on the chair, placing the cup on the seat beneath her, between her legs. She looked back at him, and lifted her tail. "Just make sure you get it in the cup," she said, grabbing a hold on the back of the chair. Shining sat there, aghast at her suggestion.

"Twil- er, Nurse Sparkle, I shouldn't- WE shouldn't!"

"It's a standard procedure," she said. He looked at his sister, kneeling backwards on the chair inviting him to fuck her. More and more he was seriously doubting that the statement was true.

"Uhh-" he hesitated. Twilight was growing impatient with her patient. She levitated her clipboard over to her.

"Are you able to achieve vaginal penetration?" she repeated the question from earlier. "I guess I better change that to a 'NO'," she said, mocking him. He narrowed his eyes at her. "Let me just get my big, red, permanent marker and write that in in your medical file. 'EN, OH', 'Unable to perform'," she said out load. "Hmm, I wonder what else you lied about... I bet the ability to bring a mare to orgasm is another EN, OHhhhhhOOOOHHHHH!"

Twilight moaned out as he mounted her, bringing his tip to bear against her wet entrance. Another aggressive advance of his hips and he pushed the tip of himself inside of her. It was just a couple of inches at first, but he re-positioned his legs and pulled back on her hips with his hooves, driving more of his length into her. Twilight moaned again as his medial ring slipped inside of her, stretching her wider. He backed off a little, letting more of her wetness lubricate his thick, veiny shaft. He pushed back in the rest of the way, his wide tip butting against her cervix deep inside as his balls slapped against her clitoris, sending tingles up her spine. With his engine's piston well-oiled, he hesitated no longer, jack-hammering away on her. He leaned down and nibbled her ear.

"You were saying?" he hissed as he continued to relentlessly fuck her. She smirked. She knew her brother better than anypony. She knew exactly what to say to get him to do what she want. Years ago, when she wanted cookies, and now, wanting entirely different 'cookies'.

It took all she had just to keep herself from being fucked right out of the desk chair. He was really enjoying it now. Her tightness was a refreshing change. Not to say that Cadance wasn't. But a being married to Shining and trying so often to have a foal had caused her to... adjust to his size. Clearly Twilight did not have such regular action from something of his size. Her snug box was positively heavenly, gripping the veiny ridges of his shaft as he slid in and out of her. Even kneeling on the chair, he was a good deal taller than her, fuck downwards into her, against the g-spot of her vaginal front wall. She could feel her climax building with each thrust. "Ability to achieve erection?" he asked her.

"Yes!"

"Ability to penetrate?" he asked, punctuating the sentence with a particularly hard thrust.

"Yes!" she answered again, even more enthusiastically. He quickened his pace, sensing her impending peak approaching.

"Ability to bring mare to orgasm!?" he asked, sending his hips into a blur, pulling her tail with a free hoof. Twilight felt the knot that had been building in her tummy snap free. Her vaginal walls pulsed and gripped his cock, even as he continued to thrust. Her fresh rush of wetness spurted out of her vagina around his thick cock as she came, hard.

"YEEESSS!!!" She cried out, thankful for the sound-proof ward on the walls and door of the room. Shining grit his teeth and tried to keep going through her orgasm, but her tightness and the dirtiness of the taboo was just too much. He could feel his balls tightening as the pressure at the base of his shaft built. Twilight could feel him swelling thicker inside of her as his humping grew more and more frantic. He was so used to trying to have a foal with Cadance, his body moved on auto-pilot, forgetting about who the mare was under him. She tried to catch her breath to call out to him. She felt the tip of his dick flare wide inside her as he slammed it home, pressing it squarely against her cervix, deep inside her pussy.

"Ngh, NO! In the cup!" she cried. But it was too late. She felt the first throb of his cock, the first bout of cum rocketing up his shaft, bursting inside her with white-hot seed. The sudden feeling of fullness from his tip flaring sent her reeling into a second orgasm. Her 'uterine contractions during orgasm helping to propel sperm into the cervix'. It was a confusing rush of endorphins and adrenaline. The second rope of cum felt even bigger as he pumped more cum into her pussy. "SHINING! NOT INSIDE!"

"OH Shit!" he realized, snapping back to reality, trying to pull out. But the combination of his wide flare and her tightness amidst her own orgasm made it difficult. He pulled away as hard as he could without hurting her, pulling free with a wet 'plop'. The third and subsequent ropes of cum he aimed into the cup between her calves, filling it about a quarter of the way by the time his cock was done pulsing.

"I'm so sorry!" Shining apologized, "I, I got carried away!" Twilight didn't say anything at first, holding onto the chair as she squatted over the cup. She tensed her muscles and performed several kegles, pushing out most of his cum and a few, white gushes, filling the cup nearly two thirds of the way. She took a deep breath and levitated the cup to the counter and quickly cleaned herself, readjusting her lab coat to make herself look decent.

"Twi! I don't know what-" she put a hoof up, silencing him. She took an eye dropper from the drawer and drew up some of the 'sample' and placed it on a slide under the microscope. She leaned over and looked into the eyepiece, counting the number of sperm in the standardized field of view.

Shining waited quietly. His shaft fully retreated back into its sheath. Twilight squinted and after a few minutes she wrote down a number, applying a formula for this sort of count. She gasped and looked in the microscope again, taking a few more minutes, double-checking her count, and redoing her math.

"Better call the Canterlot Archive of Equestrian Records," she said. He looked at her, confused. "Well if my calculations are correct, and I have no reason to doubt that they are, it means you have the highest sperm count ever recorded. Based on my estimate, you have at least three hundred million per milliliter. And they are very active swimmers."

"Oh. Um, are you going to be okay?"

"Don't worry. A nurse always has a Plan B," she said, back in her professional demeanor screwed a lid onto the sample to send to the lab. "Thank you for providing a sample. And of course, everything that happened in this room is strictly confidential. Nopony will even know about it."

"Yeah," he breathed. "Right."

"Have a good evening Mister Armor," she said, opening the door for him, letting him walk out.

"Thank you, uh, Nurse-soon-to-be-Doctor Sparkle."