“That was definitely fun,” said Luna, lying sprawled on her back, drenched in sweat and smelling of sex. The bed was in disarray and various toys lay scattered around the room, a testament to the long and pleasurable night the two had spent together. “Don’t you agree?” she added, grinning at Celestia, who could only make a muffled sound through the gag still stuffed in her mouth.
Luna chuckled, and reached out to give a little tug on the collar that Celestia was wearing. “You look good collared, gagged, and well-used,” she said. “I wish I could show you off to all of Equestria like this. It’s a shame that the scandal of it would make life hell for us both. If I could get away with it, I would parade my little pet on a leash, on the streets of Canterlot, in broad daylight.” She grinned.
Celestia made another little muffled noise, and squirmed a little bit. Luna just grinned more. She knew Celestia liked such threats. They were a pair of frustrated exhibitionists, wanting to show off for all the world, and utterly unable to due to their position.
“Ah well. You have been a good pet tonight, so come, lay beside me. I’ll let you go and return you to your room before morning, but for now you’re still mine.”
Celestia crawled forward on the bed and dared to rest her head on Luna’s chest. Luna released her gag, but left the collar on, and the two slipped together into slumber, both spent and satisfied by their night’s play.
The next morning the pair were seated at a formal breakfast, side by side at the head of the great table, with various nobles and dignitaries ranked along it. While Celestia was in mid-bite, Luna leaned over and whispered in her ear, “I know you have a clear afternoon, sister mine. I have plans for it. Come to my quarters after noon court.”
Celestia managed to keep her serene public mask in place, but the tone of Luna’s voice promised terrible, wonderful, dirty things, and it was all she could do to keep from blushing. She swallowed her bite of omelet and said, “Oh?”
“Oh yes. I am going to make you my bitch, Celestia,” whispered Luna, so soft it was almost inaudible, but every word seemed to burn its way into Celestia’s brain. “And then I’m going to take you on a little walk and show you off to all of Canterlot, leash, collar and all. What do you think of that?”
Celestia had to clear her throat twice before she could reply. “I think you promise dangerous things, sister.”
Luna only laughed, and left Celestia wondering all day exactly what she had in mind, and how she would keep her promise without putting their reign in jeopardy.
When noon court concluded, it was all Celestia could do to not wink directly to Luna’s quarters. Such haste might draw comment, though, so she merely walked at a sedate pace, even though inside she was half mad with curiosity, mixed with lustful anticipation. She knew Luna, as both sister and Mistress, and she could well imagine the sort of terrible, raunchy, forbidding things Luna might get up to, even if she couldn’t guess at exactly what she had in mind for this afternoon.
Luna’s door was closed, but no guards stood outside it, so Celestia was able to slip inside unseen. Within, she found Luna waiting.
Her sister’s grin was absolutely predatory as she said, “You’re here on time. Good! You’ll be delighted to know that I’ve found a way to parade you as my pet, and show all of Equestria what a needy bitch you are.”
Celestia’s cheeks instantly flushed pink. “Surely that isn’t possible.”
“Disobedient pet!” Luna cuffed Celestia lightly across the cheek. “Never contradict your Mistress! It is possible. Now be still and let me show you how.”
Luna’s horn was glowing, and Celestia, after flinching from Luna’s admonishing slap, held obediently still and let Luna cast her spell.
The magic wrapped around her with a cool, familiar blue glow. Warmth and an electric tingling sensation flowed through her body. She could tell it was some form of transformation spell. Then the glow brightened and the world vanished into a brilliant blue-white light.
When it returned, Celestia was looking at the world from much lower down. She blinked a few times, and shook her head. Her ears flapped about as she did so. Startled, she twisted around, trying to look at herself. Luna laughed, and pointed a hoof at a large mirror in the corner of the room. Looking into it, Celestia saw that she had been turned into a dog. She was tall for a dog; long-muzzled and lean like a greyhound, but with silky, fluffy, pure white fur much longer than any greyhound’s, especially on her tail and ears.
“Yes, I think being a saluki suits you,” said Luna, still grinning. “And now you finally look like the bitch I know you are.”
Celestia found herself whining in the back of her throat.
“Sit,” said Luna, and Celestia dropped quickly to her haunches.
“Good girl.” Luna smiled and patted the top of her head with a hoof. “I think you see how this is going to go, yes?”
Celestia gave a little bark, her tail wagging, and Luna smiled again. “Good. You can bark twice for ‘no’ if you need to. But I don’t advise over-doing that. Good bitches don’t say ‘no’ to their owners.”
Celestia barked once again.
“Now, this spell is a rather fragile one. It is easily destabilized by anything that doesn’t suit the form you currently wear. Which is to say that you’d better act like a dog, or else you’ll end up turning back into an alicorn in public, and wouldn’t that be embarrassing?” He grin turned wicked. “Just imagine it, everyone in Canterlot seeing that! Although you really don’t need to worry, I’ve built in some helpful features. The spell itself will hold you rather strictly to proper behavior when I’m not around to remind you. That way you won’t risk changing if I’m not there to explain things.”
Celestia nodded. Her whole body was tensed at the thought of being revealed like that. Even what Luna was actually going to do felt incredibly daring.
“Everything should go quite well, even if I have to nip back up to the palace to take care of any official incidents. Just let me get you properly equipped...” Luna turned and pulled a broad leather collar out of thin air with her magic. She buckled it around Celestia’s neck, and clipped a matching leash to it. “There. Perfect. You’re a very pretty little bitch. Let’s go show you off. Heel.”
She trotted out of the room, the end of the leash in her magic, but Celestia obeyed the order to heel and kept the leash slack. Luna grinned and gave it a little yank anyway as she walked through the palace halls. All around them, familiar ponies went about their business, some pausing to give Luna and her pet a glance, but none of them knowing what they were truly seeing.
Alicorn and canine went out the palace gates and down to the streets of Canterlot. Luna strolled through the streets, nodding greeting to ponies as she passed. Celestia stayed at her heels, trying to look and act like a normal dog.
“Auntie Luna! Out for an afternoon constitutional?”
Celestia halted at the far, far too familiar voice, until the collar jerked at her neck, startling her back into motion. Luna continued walked, but nodded a cool greeting to Prince Blueblood. “Indeed.”
“I didn’t know you had a dog. Lovely animal. What breed is it?”
A sudden mischief flickered in Luna’s eyes and she smiled a tiny, sly smile as she abruptly halted. “She is very pretty, isn’t she? She’s a saluki.”
“Ah. I keep dogs myself, you know. Only the highest quality of show purebreds, of course.”
“Of course. Do you train your own dogs?”
Blueblood looked affronted. “Perish the thought. I haven’t the time to spare for such things. I have ponies to do that for me.”
“I see. I’ve trained this dog myself. I find it quite... rewarding to teach her her place. Shall I have her do a trick or two for you?”
“Oh, I suppose.”
That little smile crossed Luna’s face again. “Lie down girl,” she said to Celestia.
Celestia found herself giving a little whimper at the back of her throat. It was humiliating to perform for her nephew. Thank the stars Blueblood didn’t know who she was, or she’d never live it down! But she knew better than to do anything but obey, so she lay down on her belly in the street.
“Good girl.” Celestia wagged her tail at that. “Now roll over.” Celestia rolled over, feeling horribly exposed as she did so. Nothing that had happened so far was remotely sexual, yet obeying Luna had such associations in her mind that her hindquarters were quite damp. She hoped that nopony could tell her state of arousal as she rolled.
“Beg.” There was a hint of laughter in Luna’s voice as she turned to Blueblood and added, “She’s very good at that one.”
Celestia whined again, faintly, but sat up on her haunches and lifted her front paws in a begging position.
“And finally, kiss my hoof, girl.” Luna held out one front hoof to Celestia, who was slightly surprised. She’d been expecting the typical “shake” as the next command. Still, she knew what Luna wanted, so she obediently licked Luna’s extended hoof.
“Oh, I say, that’s a very good one! I should have my dogs learn that, it’s quite amusing.”
“It is, isn’t it?” Luna grinned. “Shall I have her lick yours, too?”
Celestia cringed and bit back another little whimper.
“No, I really must be going. It has been a pleasure, Auntie Luna.”
“Likewise,” said Luna, as Celestia breathed a sigh of relief. She put up with her odious nephew because she must, but the idea of having to lick his hoof was insanely humiliating.
“That was fun,” said Luna quietly as they continued on their way through the city. “I know you’d have eagerly licked his hoof if I’d ordered you to. You’re such a slut. You’d probably rut him if I commanded it, wouldn’t you?”
Celestia whined again, softly.
“You’d rut him and you’d like it, you needy bitch. Humiliation makes you wet, doesn’t it? I bet you’re dripping right now.”
Celestia’s ears went flat back to her head, but Luna was right, she was wet enough that she could feel a trace of it on her inner thighs as she walked.
Luna just looked back at her and gave the leash a tug, grinning. “Come on, my little bitch sister. We’re almost there.”
Celestia looked ahead and recognized Hazel Park, one of Canterlot’s largest parks. The weather was clear and sunny, and though the park was not crowded on a weekday afternoon, there were ponies here and there, strolling, enjoying the fine, sunny day.
Luna sat on a park bench. Her horn glowed and the leash and collar vanished with a little “pop”.
“Run and play for a while, puppy. We could both use a chance to relax a bit. Go have fun, but stay in sight.”
Celestia barked an affirmative, then turned and ran off over the clipped grass. It was good to just run, she couldn’t even remember the last time she’d had a good gallop. This body was built for running, even more so than her equine one. She stretched her legs out and practically flew.
Before long, however, she started to tire. Sight hounds weren’t endurance runners. She slowed and circled back towards Luna, trotting with her head up, her tail wagging. As she did, though, she noticed another dog approaching her. It was probably a mutt; a big, rangy dog with a wiry black coat and a broad, blunt-nosed face.
The dog sniffed at Celestia’s nose. She sniffed back politely, and then felt strange for trying to be polite to a dog. The dog circled around her and sniffed her very impolitely, and that distracting thought vanished in embarrassment. Of course dogs sniffed each other’s hindquarters, but she wasn’t about to return the favor this time! She walked away from the dog, but it followed, still sniffing at her intently.
Annoyed, Celestia trotted faster, but the dog stuck with her. She stopped and turned, giving the dog a low, warning growl. This didn’t seem to bother it at all. It simply returned to sniffing her intently, panting excitedly as it did so. Celestia growled a little bit louder. Why wouldn’t it just go away? What could a dog possibly be so interested in? It seemed more excited, and more obsessed, than an awkward colt getting a first date. Why...
Suddenly Celestia realized why. She clamped her tail down between her legs and turned, snapping at the mutt. She was not going to let a horny dog have his way with her!
Even the snap didn’t deter the dog, though, he went so far as to shove his nose beneath her tail, panting and snuffling.
Celestia sprinted away from the dog, towards Luna. Surely her sister would help her, if she noticed what was going on. But even as she ran the last few yards to the bench where Luna was sitting, she could see that Luna was already watching, a faint smile of amusement on her face.
Halting at Luna’s feet, Celestia looked up at her beseechingly. The mutt caught up with her and started sniffing her again, but Luna only laughed. “Poor Celestia. Have you found an unwanted suitor? You’d better not do anything un-dog-like, you wouldn’t want to be revealed here in public, surrounded by ponies, would you?”
Celestia glanced around. It was a lovely spring day, and though the park wasn’t exactly thronged, there were certainly plenty of ponies in sight. She whined and tucked her tail lower, then yelped as the mutt shoved his muzzle back under it, his cold nose making intimate contact with her canine pussy.
Luna laughed again, but just watched. Celestia spun around, growling. The mutt ignored the growls and circled behind her again. This time he reared up slightly, obviously trying to mount her. She side-stepped, still growling. She bared her fangs, trying to look as intimidating as possible, but he just attempted to mount her again. Maybe if she actually bit him it would discourage him, but she couldn’t quite bring herself to harm a dumb animal.
Whining low in her throat, with the dog once again trying to mount her, Celestia turned to Luna, only to find that her sister had risen and was walking away. She barked, a high, frantic yelp, and Luna glanced back. “Have fun,” said Luna over her shoulder. “I can’t have everypony thinking I’m an irresponsible dog owner, so I will be keeping my distance. I’ll keep an eye on you from over there.” She trotted off, and Celestia might have gone after her, but she’d held still a little bit too long while listening to Luna, and the dog had managed to get himself properly atop her, his chest on her back, his front paws wrapped around her, and his dick, narrow, pointed and entirely unlike a stallion’s, thrust suddenly into her.
Celestia yelped in surprise. The dog’s cock pushed into her easily, for though she didn’t want to admit it to herself, her situation had left her pussy soaking wet. She stood, trembling, trying to decide what to do. She might still try to flee from the animal, but did she really want to? This wasn’t what she’d hoped for. Or was it? She whined softly, uncertainly. The dog didn’t pay that any more attention that he had her earlier growling. He was an animal, primitive and primal, and all he cared about was one thing. His hips jerked rapidly, shoving his cock in and out of her, thrusting hard and fast as he sought his own pleasure.
Still whining softly in the back of her throat, Celestia took a few half-hearted steps forward, but the dog followed easily, barely even losing his rhythm. She could feel something else happening as he thrust roughly into her. Her pussy was being stretched more and more with each thrust, as the knot at the base of the dog’s dick started to grow. Soon the dog wasn’t really pulling out anymore, because he couldn’t, his knot was too large to come out. Celestia felt herself rocked back and forth with each jerk of the dog’s hips.
Those jerks were growing even more rapid and frantic, and then the dog pressed tight to her, his cock sunk as deeply as possible, his knot fully swollen, stretching her, and she felt the hot pulse of his seed in her as he came.
She let out a whimper that was almost a moan as his hot, animal seed filled her, then clenched her jaws tightly, realizing that dogs didn’t moan and she might break the spell if she wasn’t careful.
The flood of the dog’s cum stopped eventually, but he stayed still mounting her, his swollen knot tying them together. He licked at the back of her neck idly, and she flattened her ears and whined. She’d just been fucked by an animal, and it had been the most humiliating and yet confusingly arousing thing she’d ever done. She looked around for Luna, and saw her a little ways away, still watching, still smiling. Celestia whined again. Her sister had just watched as she’d been fucked by a dog. She pawed at the ground, as if she could dig herself away from this, or perhaps dig a hole and hide in it.
The dog wiggled his hips, letting out a little whine of his own, apparently wanting to be away now that he’d gotten what he wanted. He started trying to back off of her. Celestia stepped forward, tugging in the opposite direction, and with a pop his cock came free of her, a trickle of his cum running down her leg as it did.
With complete nonchalance, the dog trotted away, not even giving her a backward glance. Celestia sighed deeply and sank down to her belly on the ground, putting her head on her paws. What a day.
Suddenly she felt a grip on the scruff of her neck. She squirmed as she was lifted into the air in a magical grip, twisting around and looking for Luna.
“You’re a pretty thing, but we can’t have unlicensed dogs running around Canterlot,” said a voice.
Celestia managed to turn her head and catch a glimpse of a yellow unicorn holding her in the air with his magic. He was wearing a uniform that she recognized as belonging to Canterlot’s Public Works department, and the little badge at his shoulder showed the silhouette of a dog.
Animal Control. She was being taken to the pound! She twisted harder, growling, and tried to find Luna. She caught a glimpse, but her sister was looking away, at something else.
“Hey now, none of that,” said the unicorn, and magic wrapped her muzzle too, cutting off her growl. She whined in her throat, but it was soft, she couldn’t make enough noise to attract Luna’s attention. As the unicorn trotted out of the park, carrying her in his magic, the last glimpse she had of her sister was still of the back of her head. Luna hadn’t even noticed that Celestia had been dognapped!
At the pound, the unicorn put Celestia in a spacious kennel. There were other dogs on either side of her, and both sniffed a the mesh walls between them curiously. Celestia whined again, her tail tucked down. What was she doing to do now?
A unicorn mare with a light blue coat walked in. “Afternoon, Zest. Caught another one?”
“Yep. No collar, no magic tag, nothing. She’s awfully pretty to be a stray, but it doesn’t look like she has an owner. And she was loose in the park and being, ah... courted by some mutt that I couldn’t catch.”
“Courted? Is that what they’re calling it these days? She looks like she’s been bred good and hard.” The mare grinned. “She also looks like a purebred saluki! Like my dogs. Though I’ve never seen a Saluki with a coat that perfectly white before. They’re usually light fawn or cream. She’s gorgeous.”
“You think she has an owner, then? If she’s purebred?”
The mare scowled. “Maybe an irresponsible one that doesn’t deserve her! Certainly she doesn’t have an owner that can prove they’re her owner.”
Zest chuckled. “Dewcup... are you saying what I think you’re saying? The regs prohibit adopting a dog right away, we have to give the owner a chance to find her, if there is one.”
“Hah.” Dewcup flicked her ears, looking a little bit sheepish. “I guess I can’t just take her home. But sweet Celestia she’s so pretty! She and my dogs would make beautiful puppies. I wonder... if she was getting bred, she might be in heat? Most bitches won’t let a dog mount them unless they are.”
Celestia tried not to whine again at that. Even a real dog wouldn’t have let herself get fucked the way she had. How humiliating.
Zest just gave Dewcup a look, arching one eyebrow skeptically.
“What? I’m just saying. If I let a few of my best males in here and she let one or two of them mount her... And nobody claimed her... Then by next year I might have a litter of perfect white saluki pups. They’d sell for a small fortune, you never see salukis that color. It almost shimmers!”
Zest laughed. “Hey, if you want to, I won’t stop you. You’re due to go on break anyway, you can run home and fetch the whole collection, if you want.”
“I’m a registered breeder, Zest, it’s not a ‘collection’. They’re dogs, not stamps. Still, maybe I will.”
“I’ll keep an eye on these little hazards while you’re gone.” Zest gestured at the full kennels and smiled.
“I’ll be right back, then!” Dewcup trotted off, her tail swishing, obviously excited.
Celestia sat in the middle of the kennel, not even sure what to think. She didn’t want to be fucked by another dog.
Did she?
She could still feel the mutt’s cum making her hindquarters sticky. She could still feel the wetness of it on her pussy. Why had she been so wet when the dog first took her? Was she really that depraved? Another whine built in her throat, but she bit it back. Instead she lay down in the middle of the kennel and put her head on her paws. Maybe the other dogs wouldn’t be interested, she wasn’t due to be in heat. Maybe they’d leave her alone and she wouldn’t have to decide whether to let one mount her again.
Yet she couldn’t help but think that maybe they might, and she couldn’t help but feel her pussy growing warm and wet again at the thought.
Stars, she really was depraved, wasn’t she?
It seemed like hardly any time had passed when she heard the pound’s door open. Hoofsteps sounded on the cement floor, followed by the click of claws and the pad of canine feet. Celestia lifted her head to see that Dewcup was back, and was holding the leashes of four salukis in her magic. Celestia licked her lips, looking at them. They were all tall, lean, beautiful animals. One was pale fawn, one was black with splashes of tan, the other two were a ruddy golden brown.
Dewcup hooked all four leashes on a hook in the office area, then she grabbed something from a shelf in her magic and approached Celestia’s kennel. At first Celestia couldn’t tell what it was, but as Dewcup opened the kennel door, she saw that it was a muzzle, with a short leash attached. Celestia cringed away from it, but Dewcup scruffed her expertly and slipped the muzzle over her head before she could really struggle. Then she took the short leash and tied it to a ring set in the kennel’s wall, putting the knot so close to the muzzle that Celestia was stuck with her nose practically touching the wall, hardly able to move at all.
She tugged instinctively at the restrictive muzzle and leash, but of course that accomplished nothing, she was still stuck there, unable to do more than move her hindquarters about a bit.
“I think I’ll start with Bobo.” Dewcup trotted back to the office and picked up one of the leashes before coming back to the area with the kennels, leading the fawn colored saluki. “He’d father the prettiest pups with the white coated bitch, if she lets him. I’ll give them all a try, though; you can’t tell if a bitch will get with pup the first time, after all.”
Celestia flattened her ears, a little whimper escaping her in spite of herself. Was it a whimper of fear, or of desire? She wasn’t entirely certain.
Dewcup opened the kennel door and unclipped the leash from the dog’s collar. He didn’t hesitate, he slipped through the door before it was even halfway open and started sniffing at Celestia with obvious interest. Without really meaning to she wagged her tail a little. He lowered his head to sniff under it. Celestia shifted uncertainly, tugging again at the leash that held her. The dog pushed his muzzle under her tail and licked her.
She shuddered. Sweet stars, he was licking her pussy. He was licking the mutt’s cum off of her pussy. She whined. She didn’t know if she wanted this or not, but it didn’t matter, she was utterly helpless to prevent it. The dog could do whatever he wanted to her, there was nothing she could do to fight it. She tried all the same, shifting and wiggling, even trying to gather her magic somehow, but it accomplished nothing, she remained as she was, and the dog continued to lap under her tail.
It felt so good. Celestia shivered, trying to lower her tail between her legs, trying to deny how good it felt. Yet she couldn’t deny it. She would have moaned if she could have, but now that she was away from Luna, the spell wouldn’t let her.
Then the dog was moving forward, rearing up, his paws on her back. It was so like the way a stallion might have mounted her, yet he wasn’t a stallion, he was an animal. She whined again, deep in her throat, but there was nothing she could do to prevent the dog from taking her.
Indeed, his cock was already rubbing at her pussy as he thrust his hips, seeking the right angle to enter her. She squirmed under him as he thrust in, that strange, animal dick filling her tight passage fully, sinking in deeply, almost to the point of pain. His dick was a little longer, a little bigger than the mutt’s had been.
Soon she felt his knot too, stretching her, filling her even more. She pushed back into it, then whined as she realized what she had done. It wasn’t enough that she’d been forced to let the dog mount her, now she was acting eager for the animal’s dick.
But sweet stars it felt so good, the knot filling her more and more until it locked the dog to her, his frantic, urgent thrusts moving them both together as he had his way with her.
Celestia stopped resisting, mentally or physically, and pushed back against the dog with each thrust, feeling his dick deep within her as they moved together in a primal rhythm. A moment later she was rewarded with a flood of cum that spurted deep into her, filling her already semen-flooded inner passages even further with hot, thick canine seed.
“She does seem to be in heat, she’s a pretty eager bitch!” Celestia’s head jerked up as she heard Zest, and realized that both ponies were watching her. She felt herself grow hot with shame, and she whined softly. The dog didn’t care, though, instead he slid his front paws from her, twisting himself oddly, until he and Celestia were standing rump to rump, something she knew mating dogs did while tied, but hadn’t thought to expect. That pulled at his surprisingly flexible dick, which was still massively knotted, filling her pussy tightly. She felt it tugging within her, and another shiver of pleasure went through her.
The dog wasn’t terribly patient, as they waited, stuck together. He wiggled and squirmed, and Celestia whined and whimpered with each movement, feeling impossibly turned on. Finally his knot shrank enough for him to pull free and he trotted to the door of the kennel, where Dewcup let him out. Celestia glanced back at the mare, who was looking her over rather clinically. Cum was leaking down her legs again, matting her white fur. Behind Dewcup, Zest was watching too, and his grin was a little less detached. “They sure go at it, don’t they?” he said.
Dewcup snorted. “Pervert.”
“You know it.”
“What, do you want her next, then?”
He laughed. “I’m not that kind of pervert. But you gotta admit it’s interesting.”
“It’s what dogs have to do so that I can get lovely puppies. Now hush and let me go get the next one.”
The next one. Sweet sun and stars.
Several hours later Celestia heard the door to the pound slam open. She was so exhausted she almost didn’t lift her head to look, but then she heard her sister’s voice.
“I am here for my dog, where have you put... Ah, there.” Celestia slowly looked up to see Luna trotting towards her, the two pound employees staring at her in shock.
“P-princess Luna. This is your dog?” stammered Dewcup.
“Indeed,” said Luna. A faint frown appeared on her face as she drew closer and saw the state that Celestia was in. “What have you been doing to her?”
“Look, we didn’t know she belonged to you,” said Zest. “We didn’t know she belonged to anypony.”
“She didn’t have a collar,” added Dewcup. “Or a magic tag. Dogs are supposed to be licensed.” She flushed, realizing that she was nearly lecturing one of the Equestria’s rulers. “I’m really sorry, we didn’t know!”
Luna gave a little cough. “Ah, well... I just acquired her this morning. But what exactly did you do?”
“She’s so pretty, and I keep salukis. I thought, since she wasn’t owned, she’d give me beautiful puppies. It seemed like she might be in heat, so I bred her with my dogs.”
“I see.” Luna’s voice was flat, but then she sighed. “It’s true that you didn’t know she was owned, and that is entirely my mistake. Thank you for finding her. I shall take her home now.”
“Of course.” Dewcup hurried to open the kennel door.
Luna produced a collar and leash from thin air once again and fastened them to Celestia. “Heel.”
Celestia, weary but very glad to be rescued, rose and obeyed.
The pair walked together out of the pound and along the city streets, climbing towards the palace. The sun was low in the sky, Celestia would need to be changed back so she could set it soon. As they walked Luna chuckled and said, in a low, private voice, “Well, it seems that even those ponies at the pound could tell you were a needy bitch. Did you have fun, being bred to all those dogs?”
Celestia made a huffing sound, but didn’t bark in answer.
Luna chuckled, but the rest of the walk back to the palace was silent. Once they were safely in Luna’s room, Luna said, “You’ve no doubt had enough excitement for today, so it’s time to turn you back to your pony self.” She grinned and added, “Though I know you’re still a bitch, whatever form you wear.” Her horn glowed, and Celestia felt magic wash over her.
Wash over her was all it did, though. The magic slid over her fluffy coat but didn’t sink in, leaving her still a dog.
Luna frowned. “That’s odd.” She cast the spell again, but again it had no result.
Celestia felt her heart sinking. Luna was a master at shape-changing magic. If she couldn’t get the spell to work then something had gone very wrong indeed. She tried to gather magic herself, but without a way to focus it she could get only the most diffuse power, certainly not enough to change herself back.
“This is not good. I don’t understand what’s wrong. The spell should be easily reversible! I think I need to do some research. Meanwhile...” she looked at Celestia and shrugged. “Meanwhile I suppose Princess Celestia is taking a sudden trip abroad, and my new pet saluki will just have to hang around.”
Luna researched for three days, growing more and more frustrated with her inability to discover what was wrong. Finally she set down the latest tome and turned to Celestia, who was resting under the table with her head on her paws. “I have one last avenue to explore. It doesn’t seem likely, or even possible, but perhaps...” She sighed and rubbed a hoof over her face. She’d been dealing with ruling all Equestria while also spending every spare moment in magical research.
“Come here,” she said, and Celestia rose and moved to her side. Luna closed her eyes in concentration and cast yet another spell. Celestia felt it sweeping through her. It wasn’t a transformation spell, instead it seemed to be some form of scanning spell. It flowed through her body, then out again, and was gone.
“Buck. I didn’t think it was possible.” Luna sat down hard, looking utterly shocked. Celestia tilted her head questioningly. “This is... I don’t even know. Though I guess I have good news for that pony from the pound? She might be getting her white saluki pups. That is if they don’t come out half-pony abominations.”
Celestia froze in place, staring up at Luna. She couldn’t possibly mean what she seemed to mean.
“The scan confirmed it. The spell wouldn’t change you back because it’s not just ‘you’ in your body anymore. You’re pregnant. With a litter of five, it looks like.” With a little laugh, Luna added, “I hope you like being a dog, because you’re going to be one for the next four months or so.”
Author's Note
Yep, you just read that. Yep, I wrote it. It was fun, I like the weird ones. 
Yep, I'm open for commissions.
Oh, and yep, troll comments will just be deleted. I'm really not interested in engaging with that kind of thing right now.
