Author's Note

It’s hard to say exactly how many times Rainbow Dash has ended up “using” her diaper, much to her dismay… but still, Twilight isn’t done messing with her yet! Now, as Twilight goes to sleep, Rainbow is tied up on the bed next to her, still desperately trying not to mess and wet herself… whether or not she’ll succeed, we’ll have to see~

Hello, diapered pegasi and dominant unicorns! This story is the fourth and final part of Rainbow Dash’s Diaper Desperation! In this one, the messy, wet fun continues, and we come to a close on our little story. Enjoy this cute conclusion to the fun~ And good news: more stories about another pony being tormented by Twilight are coming! Feel free to share your guess as to who it might be~

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This story contains: FxF, unwilling sub, omorashi, diaper play, wetting, desperation, teasing, bondage, humiliation, cuddling

Word count: 2884

Never Forgotten

With a newly clean, fresh, and slightly warm diaper on, Rainbow returned to Twilight’s room, led by the leash… though, not without a quick stop at the kitchen for Rainbow Dash to drink plenty of water to fill her bladder back up.

The lights were already dim, but they now faded to pitch black. “I know I already asked earlier, but really, where am I sleeping?” Rainbow asked; at this point, although her shame still weighed heavily on her, traveling through her nerves and limbs like an electric current, she’d begun to accept the situation… and still, even in this constant cycle of humiliation and torment, she trusted and loved her friend.

“Oh, I never actually told you, did I?” Twilight pulled the covers back and got in bed; she patted the spot next to her. “Right here - with me~”

Rainbow’s face was covered in a light pink; the blush was for a different reason this time, however. “You want me to sleep with you?” She asked, a bit surprised.

“Of course - why not? It gets cold in here during the winter~” Her magic grasped Rainbow Dash, levitating her. The chain around her wings (which had been put back once Twilight was done with the chair) dissipated as she was placed into the bed next to the alicorn.

“Woah… you’re letting me free?” Rainbow asked, moving and flapping her wings a little as Twilight put the covers over them.

“Of course not~” Twilight reached out and hugged Rainbow Dash, pulling the pegasus into a tight, warm, fuzzy, comforting embrace and cuddle. “I’m going to make sure you can’t get out of here~ Though, I padlocked the doors and windows, too~” She chuckled.

“I’d think you’re insane, if I didn’t know better…” Rainbow responded, though she immediately wondered to herself whether or not she actually did know better.

“I’d be surprised if this is the first time you’re considering that possibility.” The alicorn chuckled; suddenly, Rainbow began to move downwards a bit, due to her magic. “I do want to cuddle you… but, well, if you end up needing to use that diaper, I don’t want to feel it~” She made sure that the diaper was past her own body, and positioned Rainbow Dash so that her head was against Twilight’s chest, like earlier. The princess embraced Rainbow’s head, pulling it in, making sure it was tight and secure between her furred legs and fuzzy chest, safe and comfortable, but also trapped. “There we go - that should work~”

Rainbow was pretty much under the blanket entirely at this point, but she didn’t complain - it was especially warm, as well as nice and dark. Plus, at least this way, she could hide her blush. “What if…” Rainbow started to speak; she was going to ask what to do if she had to use the bathroom, but at this point, that question seemed entirely pointless. She already knew the answer: the diaper, of course. She was almost getting used to it at this point.

“Alright, I’m going to sleep. Goodnight, Dashie~ Oh, and if you need to use the bathroom, wake me up first - I want to watch~”

“There’s no way I’m going to do that,” Rainbow quickly responded. “I mean, I’m not going to wet myself in your bed. That’d be way too embarrassing. And even if I was, I wouldn’t tell you first.”

“Not even if I removed my spell stopping you from finishing~?”

Rainbow pouted and sighed. “Well… maybe then I would…”

“Then if you’re a good pony and you tell me when you’re about to wet yourself, I’ll consider it~ And I won’t be able to change your diaper if I don’t know about it anyways~”

“Mmm… alright, fine…” Rainbow conceded; she was embarrassed to be giving in so easily. She felt like Twilight owned her.

“Perfect. Goodnight, Rainbow~”

“Goodnight.”

Twilight didn’t struggle too much with drifting off; she was tired enough from the day’s activities. Rainbow Dash should’ve been similarly tired, but she wasn’t feeling that way - the constant pressure of Twilight’s body wrapped around her was making it difficult to clear her mind. She could hear the slow, soothing heartbeat in the princess’ chest; it was distracting, but at the same time, like a lullaby, it was slowly lulling her into relaxation.

And of course, it was at that point where she started feeling the need to pee.

Already, she was half asleep; it wasn’t a good position to be in. The exhaustion of all the humiliation and shame she’d been subject to had weakened her mind and body, lowering her defenses significantly. Her hooves began to let out the lightest little shiver; she quickly pressed her thighs together, trying to wake herself out of her half-slumber, but her brain struggled to come back so quickly. The heartbeat, the cuddle, everything in this situation had tricked her mind into thinking she was in an entirely safe situation, and it was difficult to deny herself the sleep her body so desperately wanted, even as she also had the need to use the bathroom.

Rainbow reached down and pressed against her diaper; she could feel it, her bladder slowly filling as her body processed the great amount of water the alicorn had made her drink. Soon, it filled to the top; it began to ache, feeling like a water balloon that was being filled far too much. She pressed her thighs together as hard as she could, rubbed them against each other, put both of her hooves against her crotch and smushed them between her thighs, applying as much pressure as she could manage. Still, her eyes remained half-closed, her brain working slowly, too slowly, not recognizing the threat.

The pegasus squirmed, trying to keep the movements small to not wake Twilight; the last thing that she wanted was to piss herself for the third time in one day. She’d never recover from that embarrassment. “Ngh…” She gritted her teeth and focused all of her mind on her bladder, on holding it in; her squirms became more intense, her whole body now letting out intermittent shivers. She could feel it now, the urine slowly getting closer to releasing itself; she had to keep consciously pulling it back, going against her natural instinct to let it free. It was so much harder than it had been before. It was like Twilight had managed to train the pegasus to use the diaper - it didn’t feel nearly as wrong or off anymore, but it was still so humiliating.

Twilight’s grip suddenly increased; still completely asleep, the alicorn suddenly pulled Rainbow Dash up, back into a normal cuddle, ignoring the diaper completely. Rainbow’s eyes widened; she tried not to make any sounds. The princess was clearly deep in sleep; her eyes were fully shut, her mouth only moving ever so slightly with the little breaths she was taking. It was cute… and it only lowered Rainbow’s guard even further. The purple pony’s grip increased; she pulled the pegasus closer and tighter, wrapping her front hooves around her tightly and squeezing her, pulling her head closer as well and nuzzling it softly, her warm breath gently spreading across the blue pony’s fur.

Twilight managed to pin Dash’s front hooves to her side, holding them so tight she might as well have bound them with a rope. Even worse, her back legs, instead of simply wrapping around Rainbow or whatever else, slid between Rainbow’s legs, pulling them apart, making it so she couldn’t easily rub her thighs together anymore. That was what really made it the most difficult - in her sleep, the alicorn had managed to put Rainbow’s body into the perfect position to make her piss herself. It was like she’d just pulled a dam out of place.

“Twilight…” Rainbow murmured in worry, not thinking about her words. She tilted her head back and focused as hard as she could, but her bladder felt like a glass of water on the tip of a table, slowly getting nearer and nearer to the edge, where it would soon fall and spill all over, and she couldn’t reach out and grab it in time.

And soon enough, the inevitable happened - she reached the point of no return. It began with the smallest little leak, a small little spurt of yellow trickling from her slit into the diaper, almost entirely soundless. And, like a small hole in the hull, it was enough to sink the whole ship.

Rainbow’s body shook; she tried to hold back one last time, but her bladder had made its decision to empty its contents. Rainbow couldn’t help but sigh as urine streamed from her slit, quickly filling the diaper like a hose, the sound of liquid hitting the slowly dampening material being loud, even as it was muffled by the blankets. The warmth felt weirdly good to Rainbow Dash’s half-conscious self; the dampness was far more uncomfortable, but her body had grown used to this sensation. It didn’t wake her up entirely, not like it should’ve.

“Mmnnmm…” Twilight rustled and squirmed; slowly, she opened her eyes, her grip loosening itself as she awoke. “Dashie? What’s going on?” She asked, rubbing her face with a hoof. She grabbed the blankets, turning her head towards them and slowly raising them to see the source of the noise…

“W-wait, Twilight, d-don’t look!” Rainbow quickly said, trying to stop the princess… but it was too late. Twilight’s horn glowed, shining light onto the scene below, of Rainbow Dash’s diaper turning more and more yellow as it was filled.

“Well, well~ Did some poor pony have another accident~?” She grinned. “Why didn’t you wake me up sooner, Rainbow Dash? I would’ve loved to hold you while you struggled~”

“Well… you sort of did already…” the pegasus murmured, pulling her chin down and looking at the pillow they were sharing.

“Did I? Oh, I guess I wasn’t holding you in this position when I went to sleep. Sorry, I’m a bit of a sleep cuddler~” She chuckled. “Oh, you’re so adorable~ I always love seeing that nervous little blush on you~”

“Twilight…” The pegasus whined like a child who was getting embarrassed in front of their friends.

“Come on, let’s get you changed, and then we can finally go to sleep. You should rest up - I still have more ideas I want to try with you tomorrow~” Her horn glowed; the diaper was soon magically replaced. “I’ll clean you off in the morning.”

“Isn’t wetting myself three times enough? This feels excessive…” the pegasus complained.

“No way - I’m having way too much fun to stop now~” Twilight gripped Rainbow Dash yet again, pulling her into another full-body cuddle. “Goodnight, Dashie~ Try not to have two accidents in one night, ok? That would be extremely embarrassing~”

“Mmm… g-goodnight, Twilight…”

And soon, both of them drifted to sleep, in each other’s hooves…

…and following that, the week continued.

Every day, Twilight had new ideas for what Rainbow Dash was going to be doing, each one getting more and more humiliating, resulting in the pegasus messing or wetting herself two to three times daily. And of course, many pictures were taken, all featuring Rainbow Dash in a number of embarrassing, humiliating positions, treating her like a fashion model… or really, more like a toy, considering Twilight just used her magic to move the pegasus around.

The week was long and difficult for Rainbow Dash, but it felt far too short for Twilight; she had more fun than she could’ve expected. And slowly, the pegasus couldn’t help but realize that, at some points, she was enjoying herself a bit too… and it didn’t help that Twilight constantly pleasured her at entirely random times, conditioning Rainbow to almost like being in the diaper. Still, it wasn’t enough to take the pegasus so far that she developed a new kink… but by the end, she was almost yearning for more.

Finally, the last day arrived; the fun had all started on one Saturday afternoon, and now, the clock had struck that same time. “Oh, finally! Please tell me it’s really over this time,” Rainbow Dash pleaded, her diaper wet and full.

“Alright, I did say I was only going to do a week, so we can stop here. I also just ran out of diapers, so I couldn’t keep going, even if I wanted to - you’re lucky, Dashie~” The diaper floated off; a magic force cleaned Rainbow’s backside in seconds.

“Wait, you could clean me with your magic the whole time!?” Rainbow looked at her entirely spotless backside in shock. “You didn’t have to do it by hoof at all!”

“That’s right~” Twilight responded, snickering. “I just wanted to clean you myself. It was more fun that way~” The diaper floated over to a trash can, accompanying a slew of other filled diapers, the amount somewhere in the high 10s. “And I know you liked that part, too~”

“Mmm…” Rainbow looked to the side, with one last embarrassed blush. “Can I go now?”

“Did you learn your lesson?” Twilight responded, looking Rainbow in the eyes. “I don’t want to have to do this to you again~ Or, I should say, you don’t want me to have to do this to you again… because I will do it, and I will enjoy it~”

“I swear I learned my lesson! From now on, I won’t do pranks that often. I’ll make sure to space them out so they don’t become a nuisance to other ponies. I really mean it - I don’t think I could ever forget this, not after all of that.”

“Good!” Twilight grinned and patted Rainbow on the head. “Alright, you’re free to go! But, well…” Twilight held Rainbow’s chin and pulled her close; the alicorn whispered, “If you ever want to be punished again, I’ll make sure I have plenty of diapers~” Twilight planted a light kiss on Rainbow’s cheek.

Immediately, the pegasus’ face went bright red; she pulled away, her heart beating rapidly. “No chance, I would never do something like that willingly!” Even as she said those words, she wasn’t entirely sure if they were true; she had some mixed feelings about this. It was hard to pinpoint exactly why. Was it the domination from her friend, the sadistic glee Twilight clearly felt, the humiliation, being taken care of so tenderly… she didn’t know.

“Hmm… If you say so~” Twilight said, her voice making it clear that she didn’t believe the pegasus. “I’ll see you soon, Rainbow Dash~”

The pegasus bit her lip, her blush glowing. “Yeah… I-I’ll see you soon, Twilight.” And with that, she was gone.

Twilight watched the pegasus fly back up to Cloudsdale; it had been fun, but all good things must come to an end, of course. She pulled out the many pictures she’d taken, already reminiscing… and then, she looked up to a corner of the library… and her horn glowed. There was a waver of magic, and then, a camera-like structure appeared. “She has no idea~” Twilight said to herself, smiling sadistically. “I shouldn’t have worried - of course Dashie wouldn’t notice the secret cameras I have in each room. I have a whole lot more footage to enjoy… and a lot of planning to do for next time~”

This certainly wasn’t over yet; Twilight already had ideas, and Rainbow Dash was the perfect subject of her bullying. Many lessons were yet to be taught.