Spike awoke slowly, feeling well-rested. He was warm, but oddly uncomfortable. Did Twilight tuck him in too tightly last night? Wait… no. She hadn’t tucked him in in a while, not since he got his wings. Speaking of which, he really needed to stretch the things out, but couldn’t. The more he woke up, the more he realized that he was unable to move in this dark room. Not only that, but something warm and fuzzy was pressed against his front.

“Mmmh, five more minutes,” cooed a sleepy filly.

“Sweetie!?” Spike exclaimed. He now realized that the fuzzy thing against his front was Sweetie’s back. The reason he couldn’t move was that something was binding him in place. Straps were tied in strategic areas to limit mobility, but also in such a way to avoid chaffing. Spike knew of only one pony who could be responsible.

“S-Spike?” she asked drearily. A smile came to the filly’s face as she recognized the familiar texture of Spike’s belly scales against her back. Cooing, she tried to wiggle herself closer in the hopes of coaxing him into some early morning action. However, she couldn’t. She recognized the binds much quicker than he did, having practically grown up with them.

“Good morning, darlings,” Rarity practically sang as she entered the dark room. Her horn lit and activated the magical lamps surrounding what turned out to be Sweetie’s room.

As the lights slowly intensified to let the former sleepers’ eyes adjust, the youngsters found that they were tied together on Sweetie’s bed with Spike playing the role of the big spoon. Honestly, there were far worse places and positions for one to wake up in, but anywhere in Rarity’s grasp was at least in the top ten.

“I hope you slept well. You two have a busy day ahead of you.” The marshmallow mare tittered as she strutted around the bed. Her prancing caused her plush rump to bounce enticingly while her half-erect cock flopped ungraciously beneath her, slapping her belly in a most unladylike fashion.

“R-Rarity. What’s going on?” Sweetie asked. On the one hand, she was concerned as to what devious and dastardly scheme her sister had cooked up. On the other, she was growing annoyed that she couldn’t feel Spike’s double dragon dick. If he wasn’t at least hot-dogging her by now, it meant that he’d been bound in such a way to prevent it.

“Tut-tut. Patience, darling. All good things come to those who wait,” Rarity instructed. She revealed a tray loaded with the morning’s breakfast and presented it to her captives. “I hope you enjoy your meal. All items specially chosen to maintain youthful vigor and prolong one’s endurance,” she instructed like a teacher giving a lesson.

Just as Sweetie opened her mouth to repeat her question, a sandwich was shoved between her lips. Having long since been conditioned not to resist Rarity’s whims, Sweetie chowed down on the morsel and swallowed. “You’d better eat too, Spike. I get the feeling we’re gonna need our energy for whatever’s coming.”

“Smart filly,” Rarity with an almost sadistic smirk.

With a defeated huff, Spike did just that and opened his mouth. Sandwiches were magically levitated for him to chow down on while the two were given breaks to breathe and drink the juice. It was all very delicious. Now more aware of his predicament, Spike found that his face was partially buried in Sweetie’s mane. She smelled nice. His wrists were tied under her belly, so while he could get himself a couple of handfuls of soft filly fur, it wasn’t anywhere that would make her squeal. Also, despite his best efforts, he couldn’t move his crotch any closer to Sweetie’s.

“I think that should do for now.” Rarity set the tray aside on the nightstand as she came around. She sat on the side of the bed and turned to face the bound youngsters. “I know you’re probably wondering what this is all about, but let me answer that question with another question.” Rarity cleared her throat. “Sweetie, what day is today?”

“Uh… Thursday?”

Rarity smiled flatly. “No, Sweetie. Today is the second day of something special. Tell me, was there anything that stood out to you about yesterday?”

Sweetie’s brow furrowed as she thought. “I remember waking up with a funny feeling in my tummy.”

“Go on.”

“It was like I was super horny, but more so. It’s hard to say. I remember thinking I was gonna throw up or something at breakfast. Then you came in and I…” She trailed off giggling.

“Aww, don’t be bashful, darling. It’s only Spike, you know. I’m sure he can handle the story of how you launched yourself from your chair like a cannonball and impaled your little pussy more than halfway on my cock. Oops. Did I say that out loud?” She tittered in a faux apology.

Spike felt Sweetie heat up in embarrassment. Even with his limited movement, he did his best to console her with a hug. “Hey, don’t be like that. Rarity’s got a pretty awesome cock. All the Elements do. It’s normal to want to feel those amazing slabs of meat wedging themselves inside you, spreading out your insides, filling you like there’s no tomorrow, and then…” Spike trailed off, wary to say anymore. Not only was he turning himself on, but he could see Rarity’s fifth leg standing to attention as if to answer his call.

“Such a good little Spikey-wikey,” Rarity cooed as she cupped his cheek. “Always putting your friends first and ever the gentle-drake. It’s why I chose you, you know.” Spike almost asked his question, only to get a shushing hoof from the mare. “Ah-ah. Not yet. Sweetie still needs to tell you about yesterday.” She turned to the filly. “Well, go on, darling.”

Sweetie nodded even as she squirmed. Spike’s efforts to calm her down had backfired, only increasing her arousal. Worse, she was pretty sure breakfast was kicking in as she suddenly had the urge to get up and do something to work off this newfound excess energy. “W-well,” Sweetie panted with a growing grin, “I rode you. I clung to your belly like a koala while you – nnngh! – went about your d-d-day.”

Rarity nodded. “You calmed down whenever I climaxed inside you, yes?”

Sweetie nodded. “Y-yeah. It was so…”

“Refreshing?” Rarity suggested.

“That works.”

“Almost like having a cool glass of water on a hot summer’s day, yes?” Rarity’s grin grew mischievous.

Being accustomed to Molestia’s riddles, Spike’s eyes widened in alarm when he felt that he’d deduced the answer, only to have a glowing aura pinch his lips shut. Rarity tutted her discouragement and motioned for Sweetie to keep going.

“I g-guess,” Sweetie allowed. She knew that her sister was alluding to something, but still couldn’t put her hoof on it. It was also getting harder to think as her body grew hotter. Between Spike and her sister, the smell of cock was pungent in the air. “M-my tummy’s feeling kinda funny again. C-can I use your cock like I did yesterday?”

“That depends. Can you tell me what you’ll use it for? The literal answer or a colorful euphemism will suffice.” Rarity gave her sister a moment, but there was still nothing. “C’mon, Sweetie. It feels like there’s a fire in your belly. A burning need. What could my cock do to alleviate such tension?”

“It could coo-” Sweetie’s eyes snapped open as it finally came to her. “C-cool my heat?”

“Bravo, darling! Bravo!” Rarity applauded. “I knew you’d get it eventually, but yes. Now that you have your cutie mark, you’re officially an adult, meaning that you get to enjoy your first heat.”

“But it’s awful!” Sweetie whined. “All I can think about is cock, my body is burning up, and I can’t even move to fix it!” she cried while struggling against her binds. “Please, Rarity. Just fuck me already!”

“Oh, Sweetie. I know the first heat can be troublesome. All young mares go through it. And although my ravishing mare cock would suit your needs adequately,” Rarity explained while stroking herself, “I’m afraid that this isn’t a good time for me. I have too many orders from important clients. Our usual sessions of my using you as a cock warmer simply will not be enough to satisfy you. That’s where Spike comes in.”

Spike furrowed his brow. He thought he understood, but something about Rarity’s tone left him feeling especially uneasy. “So I just need to fuck her? I can do that, no problem.”

“Not with these binds keeping us apart where it matters,” growled Sweetie as she strained to push her ass up against Spike.

“Alas, it is not that simple, my dearest Spikey-wikey. A young mare’s first heat can be – how do I put this delicately? – demanding. Throwing my sister on the bed and lovingly ravishing her body as you would usually do will not suffice. It is not enough that you fuck her,” Rarity explained over Sweetie’s ongoing whining. “You must fuck her stupid. You must appease her pussy beyond the point of climax, beyond physical exhaustion, and perhaps even beyond sense.” That last part was said with Rarity’s special brand of sadism.

Spike felt his guts sink. “W-wait. Heat lasts days. W-what about Twilight?”

“There’s no need to fret, darling. I’ve properly compensated her for your time. Essentially, I have purchased your services as a stud until my sister is satisfied.”

“Pleaaase,” Sweetie begged, still trying to push her butt back.

The look in Rarity’s eye grew wilder as she licked her lips and lit her horn. “Of course, darling.”

The binds were strategically adjusted to loosen in some areas while others tightened. Both youngsters gasped in blessed relief when Spike slammed his hips into Sweetie’s backside. His double penis plunged into the young mare’s sopping wet pussy and made them both moan in ecstasy. With what control he could exert, Spike pressed himself as far as he could into Sweetie’s snatch and began rotating his hips around. Her pleasured cries were like music to his ears as he built up the friction between them.

Sweetie’s brain went white-hot with bliss. Spike wasn’t thrusting yet, but the friction of his rotations was amazing. She’d taken his hemi-penis before. The dual tips made him significantly wider than most colts and stretched her sensitive walls to an extent that she hadn’t realized she’d been craving. “M-more!” she rasped as Rarity gave her another sip of water.

“Yes, ma’am!” Spike acknowledged dutifully. He reared his hips back as far as they would go within the binds, which was also just enough for him to leave his dual tips inside, and then slammed back in. Sweetie rocked forward atop the sheets and gave a gurgling grunt sound. Spike pulled back slower this time so as to savor the feeling of his skin sliding across hers, only to stop. “You want me to fuck y-?”

“Yes! Dammit, yes!” Sweetie demanded as the others giggled at her expense.

“As you wish.” Spike slammed back in once more. Taking Rarity’s advice, he decided to experiment a little with his methods. Every few vanilla thrusts, he’d switch to a rotating motion that made Sweetie writhe. Had she not been bound, she’d likely have kicked him by now. “Wow, you’re really into it, aren’t ya?” he taunted, loving the power that came from pleasing a mare.

“Nnngh! D-don’t stop,” Sweetie whimpered.

Spike didn’t stop, per-se. He did, however, strategically slow down just when it felt like Sweetie might be getting too close. “Rarity said this can’t be an ordinary fuck,” he whispered into her ear. “I gotta make it good. Gotta fuck your brains out,” he said through gritted teeth as several rapid thrusts were pummeled into her backside, followed by slower and more caressing insertions. “Rarity says it’s the only way to satisfy you.”

Spike’s experience with mares in heat was, admittedly, limited. In Molestia’s school, most other fillies and mares had partnered up away from him, so his primary experience was with Twilight. Thanks to Molestia, that filly knew plenty of advanced masturbation spells, so his involvement was largely superfluous. All he knew for certain was that each mare experienced heat a little differently. Fucking them stupid seemed the common-sense solution, and since Rarity knew Sweetie best, it seemed like she was the closest thing to an expert for Spike to defer to.

A neatly trimmed white hoof stroked Rarity’s cock while a blue aura shaped like a hemi-penis plunged into her pussy. It wasn’t the rough and creative pace of Spike, but it was enough for the unicorn to maintain an ideal state of arousal. “So beautiful.” The words escaped her lips as her eyes drank in the youngsters. She’d watched them have sex before, but this was something else. Sweetie had never been so vocal or receptive to Spike’s thrusts. The young mare’s need was nearly palpable, which almost had Rarity drooling in anticipation of what she had planned.

Spike huffed and puffed until finally, he felt a familiar pressure build in his gut. “C-cumming!” he warned, slamming in one last time and switching back to rotations. His climax erupted forth like a dual fire hose into the filly’s snatch. The girth of his hemi-penis meant that most of his white seed was packed inside and unable to escape.

Sweetie was perfectly content with this as she cried out her orgasm. “Fuuuck!” She felt Spike’s goo slosh around in her pussy. It burned something amazing while paradoxically making her feel a little cooler. Her mind turned more lucid, so while she was still pressing her butt back to keep Spike’s cock where it belonged, she was coherent enough to appreciate other things. His scales had a unique texture against her fur and the way his arms gripped around her barrel felt oddly comforting, even if neither of them had a choice in the matter. She knew from experience that Spike loved post-sex cuddles and was prepared to enjoy this moment of respite.

“Very good, my darlings,” congratulated Rarity, still wearing that sadistic smirk. “However, that was just the warmup for today. The real challenge begins now.” As she spoke, new materials were levitated up from beneath the bed. The youngsters’ bindings were adjusted with new ribbons holding them to the bedposts while spreading sticks were applied in unusual areas that didn’t immediately make sense to the pair. Rarity paused to appraise her work, leaned forward, and gently poked Spike in the shoulder.

“Nnngh, oh fuck!” gasped Sweetie, her cheeks flushed. Spike’s seemingly slight movement resulted in an intense jostling of his dual shafts in her pussy. “S-sorry. I g-guess I’m still a little sensitive back there.”

“No need to worry, darling. It’s perfectly understandable, and also precisely the reaction I was hoping for.” Rarity then hopped off the bed, causing a shift in the mattress that pulled on both youngsters’ binds in ways that caught both off guard, making them gasp. “Ah, yes. Simply splendid.”

“R-Rarity,” Spike struggled to say. Somehow, even the labor of breathing was making him move around in Sweetie’s foal hole. “W-what’d you d-do t-t-t-nnnf!?”

Rarity’s smile was as demure as it was frightening. “Call it a bit of inspirational experimentation, darlings.” Her horn’s glow grew as a pair of shimmer’s appeared beside her and the bound youngsters. Like rippling water, the shimmers slowly calmed until the other side could be seen. Rarity turned from the youngsters, only to stare at them through the magical window. Beaming with gleeful power, her horn lit again, this time adjusting the position of the window to observe the youngsters from multiple angles. “Yes. This will do nicely,” she said before situating a bedpan behind the pair and daintily trotting toward the exit.

“W-wait!” Spike called out.

Rarity stopped and turned around, giving a look as though she’d only just noticed the drake. “Yes?”

“I… shouldn’t we get breaks or something? I promise I won’t try to leave, but-”

“While appreciated, I’m afraid that there’s no need to make such a promise, Spikey-Wikey. I know you won’t leave because that would compromise my little experiment.” Rarity tittered darkly before leaving this time.”

“Spiiike!” Sweetie moaned. “P-please don’t move so much.”

Spike gritted his teeth. He wasn’t sure how, but the slightest movements were having a disproportionate impact on where the penis met the pussy. It wasn’t just that they were extra sensitive following their orgasm. “It,” Spike grunted. “It’s like the ribbons and stuff all have a will of their own,” he panted to say. “Th-it’s like they’re trying to coerce us to keep fucking,” he said incredulously.

Sweetie turned her head as best she could to meet Spike’s confusion with her own. “W-why?” It went without saying that they didn’t need coercion to fuck. They’d do so happily of their own accord, as they’d done countless times in the past. “Wh-what’s differrrent?” moaned the young mare.

Rarity cleared her throat, drawing attention to the youngsters’ window. “I’ve implemented a few personalized modifications on this scrying window, my pets. I cannot hear your words. Only your cries of lewd and carnal bliss,” she purred, “shall grace my ears. I ask that you be patient and try not to overexert yourselves before lunch, when I shall resupply you. Can’t let those nubile bodies tucker out too soon, can we?” she tittered.

Then Spike’s heart skipped a beat. “The bedpan,” he muttered. “H-how long?”

After reading their lips, Rarity touched her chin while pretending to think. “I do believe I said until Sweetie’s heat passes. That seems like a good start.”

“Start?” Sweetie whimpered back in equally growing horror.

“You see, you two shall be fornicating nonstop for the duration of your heat. Normally, most mares would enjoy such an endeavor. However, when I say nonstop, I mean nonstop,” Rarity said with deadly seriousness. “Your bindings are based on a design I took from a museum in Canterlot, meant to amplify all movements and build one’s arousal. With a few modifications of my own, I believe that I have perfected the original design. Naturally,” she humble bragged. “Sweetie, for the duration of your heat, your every flinch will move Spike’s cock inside of you. And Spike, as you’ve likely discerned, even your faintest breathing will cause Sweetie’s young pussy to embrace you with all of her might. Neither of you can stop this, so you might as well sit back and enjoy.”

Spike had heard such lines before in Molestia’s dungeons. Ponies would be locked up for days on end and submitted to all manner of perversions, but at least they got… “Safe words! Do we get a safe word?”

Rarity tilted her head. “It appears that you said safe word. A fair inquiry, but I’m afraid such a thing would ruin my little… I suppose calling it performance art would be better. While I work, you will perform. I will listen to you, watch you, and draw inspiration from your particular predicament,” she tittered most ladylike. “I won’t lie by saying that this won’t become uncomfortable, but that’s the point. One must suffer to achieve great art, and I believe that observing your agonizing orgasms shall motivate me to create a new line that will take the fashion world by storm,” she proclaimed with a dramatic flourish. “You wouldn’t want me to miss out on such a chance, would you?” she asked in a baby voice while pouting adorably.

Before anyone could answer, the bell rang to announce a customer’s arrival. Rarity rushed to greet a stallion that the youngsters didn’t recognize. Pleasantries were exchanged, and when the stallion inevitably pointed out the scrying window, Rarity made a dismissive remark before leading the stallion to his order. The youngsters could only watch in falling spirits as their plight was ignored.

“I-I’m getting hot again,” Sweetie panted. She moaned as her butt wiggled against Spike’s crotch. “You’re filling me so good. J-just a little morrre!”

“R-right,” agreed Spike. The new bindings still let him move his hips to an extent. He pulled out slowly to draw out Sweetie’s cries of bliss. The stallion noticed, but Rarity kept his attention on the order. Spike pumped his hemi-penis back into Sweetie’s cunt. Her insides pulled on his cock each time he pulled out, scraping their sensitive genitals together. “J-just keep going,” Spike panted. “If we go at it enough, m-maybe we’ll pass out.”

Sweetie’s heat prevented her from listening too intently. Her pussy was too hungry and Spike’s cock was too slow. Luckily, she’d found that bending her back a certain way finally gave her the slack she needed to slam her butt right back against his crotch. “Agh! Nnnf! Oh yeah!” she grunted each time her butt collided against the drake with a wet smack.

Spike grunted. Even if he didn’t have Sweetie on board, his scheme could still work. They’d give Rarity a little malicious compliance by fucking themselves to exhaustion, and then being too exhausted to fuck any further. The hope was that she’d eventually grow bored and seek out an alternative form of inspiration. Even if it still involved them, at least they might be more comfortable. Thinking that this was their only chance, Spike impacted Sweetie’s pussy at full force and gave his hips a twist at the end. His already over-sensitive cock spermed into the young mare’s cunt. As they rode out their climax together, Spike found that Sweetie’s fur was growing stickier by the minute.

Meanwhile…

“Goodness, those two certainly seem determined,” the stallion said with a lick of his lips. “If you’d allow, I wouldn’t mind borrowing them for a smidge.”

“Normally I’d be happy to oblige and lend my sister to you, but I’m afraid that the drake isn’t mine to give. I’m borrowing him from another mare, you see, and it would be most uncouth to lend a creature that I’m already borrowing.”

“Ah, a true lady then,” praised the stallion. “It’s been far too long since I’ve met a mare who can demonstrate the proper etiquette in pet care. Meeting a mare of such class alone makes this venture worth it.” He turned to the order. “And this gown is a vision of loveliness. I can’t wait for my future wives to see me in it.”

“Indeed. I’ve made the material extra durable so that when they inevitably ravish you, there will be no damage. You’re encouraged to wear this gown as often as you like without any fear of wear or tear for years to come. That’s the Rarity guarantee,” she bragged.

Later, like, at the exact same time…

Spike and Sweetie heard every word. Well, more so the former. Sweetie was increasingly lucid after near back-to-back orgasms. However, she could still feel the heat’s lust at the back of her mind, munching greedily on her latest climax, but would soon be hungry for more.

“B-better?” Spike panted. He tried to adjust his position a little, only to feel tensing in his balls. How? What had he done? What binds pulled where to cause this? It was impossible to tell. “A-at least I’m too soft-” The triumphant words died in Spike’s throat as he felt his cock swell with renewed life. Why? Was it the supplements Rarity had fed them? Was his body reacting to Sweetie’s pheromones? Was this a dragon thing? Maybe it was all three and then some. Whatever the case, this was bad.

Everything faded into a blur after that. Spike only came back to consciousness when the door opened and Rarity returned. The smell caused his stomach to growl while his body ached from the promised nonstop fucking.

“Lunchtime, my pets.” Rarity set another plate of sandwiches near the pair. Some glistened from a variety of gems between the bread slices while others were downright plain in comparison. “Gracious, you two have been doing wonderfully. The sounds you’ve made and your looks of exhaustion,” Rarity trailed off with a girlish squeal. “Delightful. Positively delightful.”

“Rarity,” Sweetie whined tiredly. “I-I gotta potty.”

“There-there, darling.” Rarity touched her sister’s cheek. “It’s fine. There’s no need to hold it. That simply is not healthy. Just go. The bedpan I’ve arranged is enchanted to catch all of that yucky mess. Relieve yourself as you like, free of shame while your friend spreads your pussy wide with his double dick.” Rarity tittered at her crude language. “In the meantime, I’ve come to feed you your noon meals.” Sitting on the bed’s edge as she’d done prior, the unicorn levitated up a pair of sandwiches and offered them to the youngsters. Both were so tired from hours of semi-voluntary fucking that they scarfed their meals down in no time. “Manners, young ones,” Rarity gently chided before readying the refreshments, which were guzzled even quicker.

When the plate had been cleared off and his energy replenished, Spike saw fit to speak. “C’mon, Rarity. Can’t we just get a break?”

“I’m sorry, darling,” she said while cupping his cheek. “I truly am, but this is for the greater good. Sweetie needs to be satisfied and I need my inspiration. How could you say no to that?”

Spike grimaced, unable to think up an immediate response. He cared about them both too much to deny them. Under any other circumstances, he’d be all for volunteering himself to be used, but the last few hours had been torture. There had been next to no reprieve as the bindings, stimulants, and whatever else coaxed the young pair into a state of perpetual arousal and humping.

Rarity, as if reading Spike’s mind, giggled. “Don’t worry, my lovelies. I have every confidence in your ability to persevere.” She then beat a casual retreat before anything else could be said.

“Sweetie,” Spike called. “Sweetie, you with me?”

“Nnnf…”

“Sweetie, I know you-whoa!” Spike moved too much, shifting his cock around the young mare’s pussy. He moaned as his hips seemingly went into autopilot. His motions were weak and devoid of spirit, but they still drove him forward, back, and forward again.

Rarity didn’t have any more clients scheduled for a while, so she went to her sewing room to put some finishing touches on a few orders. Her ear fixed towards the window as the youngsters went at it, but far more pitifully than before. Spike still had a bit of fight in him, but Sweetie was barely even conscious anymore. As such, Rarity reasoned that she’d need to up the doses on the stimulants for tomorrow. More plans were formulated as the mare sat on a vibrator shaped like Spike’s hemi-penis, only bigger. It truly was a lovely shape.

Day 2

Neither Spike nor Sweetie had gotten much sleep last night. Even a dry orgasm was enough to wake them and neither had mastered the art of total motionless sleeping. Every twist or shift had the undesired effect of stimulating them into and against one another.

When Rarity came in with breakfast – two stacks of pancakes – she decided to treat herself and climbed up behind the youngsters. Both of their butts were coated in dried sex juices, but were otherwise clean of any less savory leavings thanks to the magic bedpan. “Such a lovely sight,” she swooned. “Spike, your posterior is as plump and inviting as ever. And Sweetie, since your cutie mark appeared, your baby fat has been redistributed to all the right areas. You’ve both been filling out nicely. And now, I think I’ve restrained myself long enough.”

Tugging just so on the bindings, Rarity adjusted the bound pair so that they were stacked atop one another instead of merely spooning. The unicorn adjusted the window to look directly at the confused young faces as she straddled atop Spike. He knew what was coming, but he didn’t know how to feel about it. Normally, he loved it when Rarity dominated him. But this time, should he resist? Should he try and placate her whims? He didn’t know, and that uncertainty was visible enough to send a shiver down Rarity’s spine.

Rarity purred as the tip of her horse cock prodded at Spike’s quivering anus. “Such lovely sounds, darling. But I’m afraid that it isn’t enough,” she cooed before wedging the first inch inside. Spike’s butt hole opened without delay. “Such a well-trained drake. No need for lube or even foreplay. I can just,” she stepped forward and inserted several inches in one go, “slip in without a fuss,” tittered the mare.

“Oooh, whaaa!” Spike babbled incoherently as his ass was spread. After hours of feeling his lower half going numb, it was a shock to the system to feel such stimulation permeating his anal canal. As Rarity said, no special prep was needed. His ass had been conditioned for some time to take magical futa cock without complaint. Spike continued to groan as Rarity sank deeper and deeper, spreading his ass with her mighty girth, until finally, she’d hilted.

“Ahh, that’s it,” Rarity gasped. “Your bottom feels even better than it looks,” she said while testing the pressure of his cheeks against her groin.

“Ah, I feel it,” Sweetie croaked. She could feel the bulge of Rarity’s cock in Spike’s belly. It was poking at her butt and driving her to try and take it. A second cock could only improve things, her half-baked mind convinced her.

That brought a smile to Rarity’s lips. She pulled out slowly, letting her cock glide across Spike’s insides. She sucked in a breath when her medial ring crossed his pucker, but maintained her steady pace. “Just so you know, I am not fucking you, Spikey-Wikey,” Rarity stated nobly, keeping her breathing even and voice calm. “You are my pet, my toy, and I am merely using you to relieve my desires. Any pleasure you d-derive,” she swore internally at her slip, “is purely incidental. You are here for my pleasure. Understand?”

Spike gave a long, mewling groan as his ass was used. At least Rarity was being gentle, though he reasoned that pointing this out might provoke her into turning rough. He’d be fine with that, were he not so terribly sore already. Instead, feeling Sweetie’s needful movements, he tried to match Rarity’s pacing to pass on the stimulation. As bad as things were for him, Sweetie’s heat made it so much worse. She needed him to cum inside her. Luckily, the stimulants were just starting to kick in. Of even greater import was that the aches in the drake’s joints were easing the more he moved. He hoped the same went for his involuntary lover.

Sweetie gave a relieved sigh as her aches no longer burned so intensely. However, the stimulants – whatever they were – had the reverse effect on her most pressing need. The fires in her belly were stoked beyond reason and she needed to feel Spike jizz inside her. The friction of his hemi-penis sliding along her sensitive walls was more torturous than satisfying. It was like smelling something delicious, leaning forward to take a bite, only to be perpetually held just out of reach.

After some time, Rarity’s slow and steady lovemaking gave way to a more urgent pace. Wet slaps added to the ambiance of youthful moans as Rarity slammed her hips into Spike’s plump and feminine ass. She came harder than expected and gave a surprised gasp. Plugging the drake’s anus to keep her seed inside, Rarity estimated that she’d emptied almost a quart of cum into his rectum. When her cock finished pumping the final spurts, Rarity slowly drew herself out. “Ahh!” she vocalized in satisfaction as her cock came free with a wet pop. Then she looked down at Spike’s gaping anus and marveled as it already began closing. Truly, this was one of the finest trained asses she’d ever had the pleasure of fucking.

“Not so fast, darling,” Rarity said as she lit her horn. Spike squeaked as a tingling aura kept his anal opening from closing further. Licking her lips, Rarity used her magic to reach deep into Spike’s bowels, taking every opportunity to tease along his sensitive walls. She encased the viscous goo in his depths and pulled it out. A glob of white spunk encased in magic was held out for all to witness and appreciate. “Hmm. Such an impressive quantity I’ve produced. What should I do with it?” she thought aloud.

Sweetie, too tired for words, gave an exaggerated and pleading whine.

Rarity’s smile was gentle this time. “Well, of course, you can have it, Sweetie,” she said in her baby voice. “I’m not completely devoid of empathy for my precious sister, after all.” Rarity undid a few knots in the ribbons and removed Spike’s hemi-penis from its home. Both youngsters sucked in hissing breaths as though in pain. Grinning her appreciation at these sounds and the sight of her younger sister’s gaping cunt, Rarity then manifested her aura in a shape like Spike’s dual cock. The ethereal dildo plunged roughly into Sweetie’s young pussy, making her throw her head back in a silent scream. She’d climaxed, but that was irrelevant. It was only after several forceful pumps into her sister that Rarity fed her jizz through the dildo and into the young mare’s greedy womb. Sweetie’s body went limp against the bed as she sighed her relief.

“I’ll forgive you for not saying ‘thank you’, darling,” Rarity offered charitably before reinserting Spike into her sister and retying the knots. “That quantity should tide you over for a bit, but I expect that you’ll be begging dear Spikey-Wikey for his cock in no time.”

Spike gave Rarity the most pitiful look he could muster. He wanted to beg, to plead reason, but felt helpless in the knowledge that Rarity wasn’t interested in such things. She was getting off on having them forcibly fuck one another, and a mare like her would not be so easily dissuaded from her pursuit of carnal passion.

Rarity read all of this in Spike’s expression, gave him a kind smile, and then kissed him on the lips. “You’re doing beautifully, my darlings. Just be patient and we will pull through this together, okay?” She didn’t wait for a response before leaving. Another customer had just arrived.

Author's Note

I've never written this type of forced sex scene before, and am not likely to do so again outside of another commission. It's not my thing, but I'm still glad for the experience and think that it turned out as well as it could have.