Spike found success in his sneaking; the upstairs shower was running and since he had not heard Twilight in the front room, she was likely inside. He creeped into his room and hastily changed out of yesterday’s clothes, stumbling onto his bed as he tried to pull his tail through his pants. He was not a master of hasty undressing, and did not benefit from an equine tail made of hair; he stopped his struggling when he heard Derpy laugh from the doorway. “Cleaner than Sparkler's room,” she said, smiling at him. She unbuttoned the collar of her blouse and fanned herself with a wing, but as much as Spike liked the sight, he knew better than to try anything. “I walked in on Twilight railing Cheerilee on your kitchen table.”

“Yeah, didn't expect them to go at it in the kitchen, soundproofing or not,” the dragon replied, still trying to wiggle from his jeans. He was oddly unaffected by embarrassment, even if the mare he’d lost his virginity to was standing in his doorway holding back laughter at his lack of coordination.

“Here, let me help you with that,” the mailmare giggled, striding over and plopping down next to him. She straddled his thighs for better access to his ass and the hole his tail slotted though; her fingers moved around the base of his tail and over the hem of his pants as she worked the frills under the denim, stripping him down as she went. She scooted them under her and allowed him to kick them off himself before raising up a bit and motioning for Spike to roll over. When he complied, Derpy sat herself back down on the spot she knew contained his genital slit, the obscene little gash her new favorite organ hid within; she ran one hand under his shirt leaned down, rubbing her snout against his. “And just like that, they’re off.”

The pair laughed quietly, mindful that the soundproofing did not apply to individual rooms on this floor. The mailmare relaxed and laid out over him, burying her nose into his neck and breathing in the last traces of sex that lingered on his scales. “I enjoyed last night,” she whispered, rubbing circles on Spike’s chest. “I hope that working with the princess won’t affect the odds of us having more nights like that.”

“You’re not supposed to have sex while participating,” Spike protested without thinking. The greedy, draconic part of his brain screamed at him in rage as he tried to take the words back. “I mean, it’s to prevent disease, not that I have any!” he added quickly, cursing himself for his loose tongue. “I’m clean, totally clean.” He smiled a sheepish smile and tried not to look stupid; he felt it was far too late to avoid that.

“Was I your first?” Derpy asked, blunt as a hammer. Spike tensed up underneath her and his breath hitched a bit. “You were probably the best virgin in the world last night, then. I’m not poking fun at you, either.” She meant every word of it, body still a bit sore from his actions; she probably had a little internal bruising from having her cervix pounded, but the lingering delight she felt every time she looked at Spike made it all so very worth it.

“Thanks,” Spike murmured in embarrassment even as he felt a stab of pride; it went without saying that Derpy was an absolutely gorgeous mare, putting even his childhood crush on Rarity to shame, and she was complimenting his abilities despite his complete lack of experience. Certain parts of him responded in kind, tenting his underclothes as it slipped under the hem of Derpy’s skirt as part of his brain said he should just take her again and damn the consequences. His claws wrapped around her hips and pulled her down, grinding his length against the welcoming slit he knew was only behind two thin layers of cloth, growl rising in his throat as the draconic parts of his mind briefly overtook the logical persona he always wore. A finger pressed against his lips stopped him in his tracks.

“Later,” Derpy whispered into his ear, reaching a hand under her skirt and pulling aside their respective garments. At once, Spike’s cock was pressed against her cunny, already slick with her own arousal. “Don’t thrust, just relax,” she teased, sinking onto him until he hilted, filling every bit of her. “We won’t have sex, but this feels nice.”

Spike was inclined to agree, the beast within sated by the contact; this was no carnal act of mating, but a connection between them that had no subtext and needed to go no further than they already had; in a moment, they had to part, and that was a terrible thing, but not so unbearable that they had to lose themselves. Derpy leaned over until she rested against the bed, breasts pressed against Spike’s face and straining under their confines. “Listen, Spike,” Derpy began, shifting over him as she found a comfortable spot. “You don’t mind me going through with this, right?”

Spike felt his stomach drop, hearing the unspoken question loud and clear; you won’t become a monster like your birthday a few years ago, right? had been what she meant. He himself was unsure if he could truthfully say he would not be jealous, as he very clearly remembered that greedy part of his mind he let loose the previous night; he was scared of himself, scared he would hurt somepony he cared about. “I understand you need this,” he said, settling for a middle ground; he could put Derpy and her family above his own desires.

“I’m being unfair, aren’t I?” She knew what it was like to have a partner run around on her; Dinky’s scumbag of a sperm donor had been cheating on Derpy for the latter half of their relationship, something she had known only for a month before she found out she was pregnant and the stallion subsequently disappeared. It was not a pleasant thing, being the only exclusive partner, and she imagined Spike would feel every bit as terrible as she had, even if both of them knew she needed the money provided. “I shouldn’t ask you to be okay with me sleeping with Twilight.”

“I get it,” Spike said, trying to sound reassuring, convincing, but he genuinely worried he could not keep his word.

“It’s not like I’ll only being sleeping with her, and after I’m confirmed pregnant, I’ll never have to again,” the mailmare said, pulling Spike close as she ran things through her mind. “You won’t mind me being pregnant, right?” She heard the dragon’s muffled reply, warm breath washing over her bust and his voice rumbled through her, soothing her worries a bit.

The shower’s constant white noise cut off, and just as they had when Dinky came near, Derpy and Spike separated with swiftness born of panic, leaving one partner cold and the other empty. The pegasus creeped downstairs and left Spike to care for himself. Cheerilee was still in the kitchen, freed of her magical bonds and walking about; the mailmare felt the need to apologize, but could not bring herself to do so, worried about lingering tensions even as the teacher picked up a pair of soiled panties and folded Twilight’s apron. She actually looked a bit worn out, clothes messy and mane unkempt, but that went with their new lines of work; a sarcastic smile wormed its way onto Derpy’s face as she realized she and Cheerilee had both worked for the Crown in some fashion previously, and their new jobs still fell under that category, if in a different light.

The door upstairs creaked open, breaking the soundproofing spell that had kept things so deathly silent. Spike walked down the flight, holding a laundry basket filled with business clothes and certain feminine articles, his face scrunched in barely contained laughter as he moved past Derpy, checking to see if anypony had visited the library today; it made perfect sense that it was empty, having not opened for business that morning with Twilight so preoccupied. “It’s safe to come down,” he called upstairs, voice breaking as he tried not to snigger. “I still can’t believe you held onto that thing!”

“It’s a good thing I have it because somepony forgot last night was their turn for laundry,” came the reply, quickly followed by a rhythmic clicking sound as Spike entered the kitchen and left Derpy alone in the foyer. “Please don’t be offended, Derpy; I’m not trying to be sexy or anything.”

For a moment, as the clicking drew nearer and nearer, Derpy Hooves wondered what in Equestria Twilight would need to specify she was not being sexy for, and having difficulty as the very purpose for which she had recruited the mailmare had been sexual, if not a bit scientific. Her thoughts came to a screeching halt as Twilight stepped into view; she actually gawked at what she saw, on eye going drifting away as though in defiance of what it had to see.

Princess Twilight Sparkle stood at the base of the stairs, clad in a black latex bodysuit straight from a cheesy spy film. It was a bit tighter than it needed to be, straining around her bust and bulging around her groin until the zipper’s teeth were exposed; her wings were forced through holes just a tad smaller than necessary, and the whole thing appeared to have been custom made for a mare just a bit shorter and thinner than Twilight currently was. The material was thin, glossy, designed with aerodynamics in mind the same way Wonderbolts uniforms were. Even in the warmth of summer, her nipples stood erect despite, or perhaps due to, the restriction and discomfort such a garment forced upon her. “It’s a long, boring story about why I have a sneaking suit.”

“Why the boots?” was all Derpy could bring herself to ask after a brief moment of silence. Against every purpose of a sneaking suit, even one made in such a skimpy way, it came with matching pair of laced boots that ended just below Twilight’s knees, made of the same black latex and discernible only by a change in how they shined around the edges; they ended in platformed stilettos, lending another six inches to her already regal height. The boots were also the only thing actually made to fit, it seemed; likely recent additions or blind luck on Twilight’s end.

“Rarity made them for me after she saw the suit,” the princess said as she ran a gloved hand down her side with a satisfying squeak. “I’m not sure why, though; I can barely walk in heels without breaking my ankles.”

“My oldest likes them, but I’m not a fan,” Derpy agreed. She smiled and let her mind wander a bit, snapping back to reality as a crash sounded from the kitchen.

“Twilight, you really couldn’t clean up in here?” Spike yelled out as he stumbled back into the foyer, shirt off and held at arm’s length; there was a noticeable wet mark that most certainly was not water. Twilight turned red and Derpy almost giggled at his plight. Cheerilee, however, openly laughed as she followed him out, stark naked and not holding her soiled clothes.

“At least you have spare shirts here,” the teacher said, motioning to herself. For once, she was not lecherous, and rather than make a show of herself she acted as though being nude was entirely normal; she may have had some credence in that nothing in the Golden Oaks Library was normal these days. She had also cleaned up as best she could without access to a proper bath and no stray bits of semen or vaginal fluids remained on her fur, much to Twilight’s unspoken relief; while she doubted it, a part of her mind always reminded her that somepony could look inside and see them, and at best it would appear as though she led some sort of sex club. “I put everything in the wash; not like I can walk around with cum stains on my blouse and skirt without turning heads.”

Twilight giggled and pressed her ears flat against her head as she tucked her wings in. “Sorry,” she murmured as her face turned even redder, awkward smile tugging her lips to break the tension only she felt.

“It’s alright,” the teacher chuckled. “It’s as much my fault as yours.” She put a hand on her hip pointed to the door. “I’ll go ahead and clean up while you two talk shop, if you don’t mind.”

“Floor swabbing going to be a rotating chore now or does that go with mopping?” Spike chimed in, voice intentionally nasally and dry. Cheerilee laughed and Derpy followed suit as Twilight blinked at him; that was perhaps the first time Spike had shown open acceptance of everything around him, let alone made a joke.

“Why don’t we talk about this downstairs?” Derpy asked, clapping a hand on Twilight’s latex-covered shoulder. In her gut, she was nervous, a bit nauseated, and little panicked at the idea of what she was going to agree to, especially after her last two forays into motherhood left her with only friends to help care for her foals. Legal documentation and blackmail material made it impossible for Twilight to toss her aside, and she doubted the idea even crossed her mind, but fears were fears.

“We can hold down the fort up here,” Spike said, nodding his head to the door that led downstairs; he displayed no hostility over things, much to Derpy’s relief, but she knew there was a conversation they had to finish soon.

“Go have fun while I mop up cum and Spike does whatever he does,” Cheerilee added with a wink at the two ponies in question. Twilight looked even more embarrassed, roused only when Derpy tugged her shoulder. She hesitated for a moment, but followed along, hobbling on her heels and using the mailmare as a crutch. “What do you do, anyway? Still the faithful assistant?”

“Well, until you came along, I was the one cleaning up semen.”

_-_-_-_-_-_

The lab was clinical, even with its carnal nature; metal tables lined the walls, covered by neatly ordered reports, observations, notes, and several other documents Derpy could not understand. In the room’s center stood three obstetrician examination chairs ringed by small wheeled tables with a complete set of tools necessary to probe a vagina; small metal boxes rested on their bottom shelves, unlocked and lids slightly ajar for ease of access.

“Please take a seat,” Twilight said as she grabbed two plastic folding chairs from a rack on one wall; jerking her arms, she unfolded them and slammed them down harder than she wished to, flinching at the impact. Slowly, she eased herself into the seat, latex bodysuit groaning under the strain as it stretched and tightened with her; her bust was squeezed tight and she had mild difficulty taking a deep breath, but otherwise she was comfortable. Derpy had no such issue plopping down onto the firm plastic, perhaps shifting once or twice to find a comfortable position, but otherwise had no issue crossing her legs and striking a businesslike pose.

The two sat in silence for a few brief moment as reality sank in and they each realized they had no earthly idea how to go about this. Were they both in agreement? What were the specifics they still needed to work out? Was Derpy going to opt for artificial insemination or was she wanting to go a more natural route? How would Twilight even initiate things, if she was going to initiate at all? It had been easy with Cheerilee, who was a horny mare just like Twilight was a horny mare, but Derpy was far from that; no steady partners in the past nine years, no rumors of secret rendezvous or friends with benefits. For all intents and purposes, Derpy Hooves was not the sort of mare who would agree to even consider participating in the experiment, let alone sit down in the lab and talk specifics. The princess glanced about the room in a bout of nervousness, taking in any small details she had available to distract her while she worked out the scenario in her mind; the boxes of specialty tools were open and ready for use if artificial insemination was on the table, and as she turned her gaze from one box to another, her eyes locked on something that she had not expected to see so soon.

A flash of pink from under Derpy’s crossed legs caught her attention; a little flower patterned onto an otherwise white, plain pair of panties sat on tantalizing display. It was not for a heartbeat that Twilight noticed the fabric was scrunched up and a little off center, pulled aside and stuck next to a grey furred thigh; a much more appealing sliver of pink was just next to it. Her lips were closed at the top and concealed her clit, but slowly opened the farther down her eyes went, until she had a perfect view of Derpy’s entrance; the pegasus was wetter than she would be normally, aroused either by thoughts running through her mind or the situation she found herself in. What would she feel like? Was she tight and constricting like a velvet-wrapped fist or delightfully accommodating, just begging for some rough treatment like Cheerilee?

There was an uncomfortable tightness in Twilight’s sheath as her cock tried to slip loose with no room to grow. A hand drifted towards the achy prick, intent on fixing its angle for maximum comfort; she stopped dead in her tracks when she realized nothing had been said in a few minutes and she had been staring for the majority of them. She looked up at Derpy and found her attention not entirely disliked, if unexpected. “I’m sorry,” the princess apologized for what felt like the tenth time today.

“No, it’s partly why I’m here, isn’t it?” she asked, uncrossing her legs and pressing her ears back against her head. “I’m just a bit surprised at…” she trailed off and waved a hand about in an all encompassing gesture. “I’ve never been with a mare before, much less a mare with a penis.” Her eyes trailed to the bulge in Twilight’s suit before climbing back up. “It’s not that you’re not attractive, but…”

“Oh, no offense taken,” Twilight laughed as she leaned forward. “Before this,” she began as she patted the bulge between her legs, “I only ever had eyes for stallions, well aside from a healthy appreciation for mares.”

“Glad to know I’m not the only one who’s had a bit of awkwardness here,” the mailmare sighed as she relaxed, thighs spreading as she sank into her seat. “But I’m sure you can empathize with the difference between saying a mare looks attractive and letting her stick a dick in you.”

“No less strange when you’re the mare with the cock,” agreed the princess. “I mean, I like the penis and everything that comes with it, especially the sex, but it has taken some getting used to.” She stopped for a moment and giggled. “The day I first got it, I did not know the urethra connected to my bladder since it was made just for sex, so you can get what happened when I sat down with it sheathed.”

“You didn’t!” the pegasus tittered.

“I did, all over my nightgown; it was not a fun time.” She still smiled as she recalled yelling obscenities as she jumped into the shower to minimize the mess. She spent three hours learning to unsheath at will but at least she had far fewer accidents now. “Speaking of this nuisance, do you mind?” she asked, running a finger down the zipper in front of her constrained cock.

“By all means, please make yourself comfortable,” Derpy replied, fanning herself with a wing. A normal refrigerator and a large, industrial freezer sat against a wall and pumped out warm air, making the entire lab a bit stuffy. “Don’t suppose there’s a thermostat down here?”

“Sadly not,” the princess groaned as she leaned forward and slipped a hand under herself; the latex mimicked her, squeaking and whining as it stretched. With a sigh of relief, Twilight pulled a second zipper forward until it rested just under her navel. Her half hard cock and balls flopped free and a look of tired satisfaction crept across her face. “I can’t let these get too hot,” she said, mimicking Derpy’s wing fanning. “Stupid suit holds heat like you wouldn’t believe.”

Twilight looked up at the grey mare and found she was otherwise occupied, eyes in focus and staring intently at the royal stallionhood before her. She looked a bit intrigued by it as it bobbed with the princess’s heartbeat, but there was little arousal on her end. Twilight, however, found the attention enjoyable, shaft hardening until it stood at its full, rigid length. “Already hard again,” Derpy said with a nervous giggle as undid she the first few buttons of her blouse, exposing a generous portion of her bust. “As much as I like seeing the effect I have on some ponies, and as much as I’m sure I’d enjoy having that inside me, I’m not sure I’m comfortable with it.” The mailmare looked a bit worried and shifted in her seat. “No offense to you or anything, and I still want to go through with this, but at least for now, actual intercourse doesn’t seem too terrible appealing.”

“I actually have things for just such an occasion!” Twilight said, voice giddy as she bounced to her feet, making certain parts of her anatomy wobble as she went. She walked over to a nearby rolling table and popped open a small trunk on the bottom rack before bending over to rummage through it. What little Derpy could see of the interior from behind Twilight’s perpetually wet cunny and swinging cock, the box was lined with velvet and contained a few individually wrapped packets, some of which she recognized as medical supplies. Twilight popped open one slim bag and dropped a sixty milliliter medicine syringe on the table and a small tube of what could be assumed to be lubricant. “I’ve had this bad boy for over two weeks,” she began, wrapping a hand around her shaft for emphasis, “but I’m still a mare, and I still own all the things I did before.”

Without further delay, she whipped out a long, orange rod that had clear tubing wrapped around it; it wobbled a bit as Twilight’s arm came to a stop, leaving no doubt Derpy’s mind as to what it was. “Derpy, meet Mandarin.”

Author's Note

Next update has actual sex.
And resting while inside your partner is extremely relaxing.
And remember, authors such as myself subsist on comments.