Horse Riding

You, the human, were mounted atop your tall and mighty alicorn steed known as Twilight Sparkle. Pinkie Pie stood next to Twilight’s right flank, glaring angrily at her massive rump, wishing it could be even bigger. However, Pinkie Pie's anger with Twilight’s rump did not last long. She began to drool profusely at the sight of her enormous cheeks.

“I can’t stay mad at you,” Pinkie said to Twilight’s butt, giving her right buttcheek a soft kiss with a well-defined smooching sound. “Can I eat out your pussy?”

“Oh, of course, you can Pinkie,” she said, turning to look back at Pinkie to give her a broad smile.

Pinkie moved to stand behind Twilight's massive buttcheeks. From there she leaned forward and pressed her head between her heavy cheeks, and began to feverishly lick out her marehood with her long and thick tongue. Twilight craned her neck back and cried out in pure bliss at the feel of Pinkie's tongue licking her needy sex. You only added to Twilight’s pleasure by petting her mane with your left hand, along with scratching her right ear with your right hand.

Twilight cried out a loud horsey whinny, she could not last long from under tender loving. Thus she unleashed a monsoon of marecum upon Pinkie Pie eating her out, soaking the mare behind her in thick globs of her white creamy essence. In no time at all, she was little more than a snowpony, covered from head to hoof in a thick coating of white cum.

Twilight sighed deeply in bliss. “Anon, you have my permission to engage in sexual intercourse with Pinkie Pie. I want to see if she will be affected the same way as I was by your love.”

“Yay!” shouted Pinkie Pie from behind her.

Getting down off Twilight was going to be an issue. She was a very tall mare. This issue was soon fixed with Twilight simply laying down on the floor. Pinkie hopped onto Twilight’s back and took you into a gentle hug. The mare began to lovingly nuzzle your neck. Her two front, soft spongy feeling hooves came to wrap around your waist. Your penis stood tall and proud between your legs and it came to poke her soft furry belly. Your hands came down to grasp her thick, bubbly flanks, sinking deeply into their squishy softness.

“Here comes Pinkie!” she said shouting, thankfully her voice was muffled in your shoulder.

Pinkie hoisted herself over your cock, and in one fell swoop, she dropped herself down and took your thick, long member all the way inside her. You buried your head into Pinkie’s shoulder to quiet your scream of pure bliss from the feel of her powerful marehood clamping down hard on your cock.

Pinkie Pie began to bounce her lovely fat rump up and down upon your lap, giggling as she did so. Meaty slapping sounds could be heard as her lovely rump smacked against you. You were excited at the prospect of Pinkie Pie growing bigger. The sight of Pinkie Pie's ass air ballooning in growth in your mind was enough to push you over the edge.

So with a muffled cry into her shoulder, you subsequently unleashed into her, blasting her insides with massive amounts of your creamy essence.

“Woooo! Anon is cumming inside me! I bet I’m going to get big too!” shouted Pinkie Pie excitedly, a big cheesy smile coming upon her face.

Spurt, after spurt of your creamy human spunk, blasted into Pinkie Pie. When the last of your seed unleashed inside her, you gave Pinkie a soft kiss on the lips. Your softening member came to slip out of her. However, you were taken aback when it appeared Pinkie Pie was upset. Her lower lip began to quiver, and tears began to fall down her cheeks. Her hair lost its puffiness and became smooth, and her fur became a darker shade of pink.

“What’s wrong Pinkie?” you asked softly, tenderly rubbing the back of her mane.

“I-I…. did… I didn’t grow bigger?” she said in a low voice.

“I’m sorry Pinkie. I think Anon only affects me with growth,” said Twilight.

“I wanted a big bouncy castle of an ass! Everypony could have fun bouncing on it!” Pinkie wailed in grief and buried her head into your shoulder.

You began to leave a series of kisses on the distraught mare’s neck. Along with petting her mane at the same time. “There there, Pinkie. You are still a sexy mare.”

The mare lifted her head and looked at you with hope in her eyes. “I am?” she said in a low voice.

“Yeah, size isn’t everything.”

A big happy smile came upon her face, her hair regained its puffiness, and she made a squeaking sound like a dog's chew toy. Her fur regained its bright pink color.

“How about we go for that walk?” said Twilight.

“Can I come?” asked Pinkie Pie.

“Err, later. Pinkie Pie, I want some alone time with Anon.”

“Awww!” she whined sadly.

“Sorry, Pinkie. I’ll make it up to you at some point,” you said, giving her mane a tender pet.

Pinkie Pie crossed her hooves, and huffed, and spoke in a grumpy tone. “The best way you can make it up to me is finding a way to make my ass air balloon in growth so I can become a true balloon butt. I want a massive bouncy castle ass. It’s not fair that only Twilight gets bigger from your love.”

“We’ll try again in the future,” you turned to face Twilight. “Let's go for that walk.” Twilight made to walk to the front door, leaving the library a complete mess. “Uhhh, should we clean up the library?” you asked.

“Eh! Spike will clean it up,” she said dismissively, waving her right hoof nonchalantly.

Twilight made it halfway through the front door before her thick, bubbly flanks got her stuck in the doorway. Her ass was too fat.

Twilight blushed profusely. “I don't want everybody seeing my big fat ass right now. Can we do this walk somewhere more private?”

“Yeah, sure.”

With the flash, Twilight teleported you and herself into the middle of the woods. The Everfree Forest to be exact. It was quite dark and creepy in these woods.

“Isn’t this place dangerous?” you asked in a worried tone.

“Not to brag Anon, but I'm basically a demigod thanks to you. I am nigh-invulnerable as an alicorn. I think I'm the most dangerous thing in this forest. Now, let's go for this walk. No animal will not dare to approach.”

Twilight demonstrated her point by casually lifting a massive boulder up off the forest floor with her right hoof. This boulder was about half the size of her body, and she was holding it up above her head with not even a hint of struggle. She then subsequently slammed the boulder against her forehead. It shattered into dust upon impact against her. She was completely unfazed, and not a scratch was left on her.

“You are… are a strong pony,” you said in awe.

True to Twilight's word, everything in the forest kept a wide berth from her as she walked through the forest with you on her back.

You and Twilight’s bond was growing more and more as you rode upon her. She is still very interested in horse riding, which gave you an idea. So you had Twilight magically create a set of riding tack just for herself, which is black, that made Twilight look very sexy in your view.

You and Twilight are alone in an open, long grassy area within the forest, Twilight wore a riding tack, which includes a saddle with stirrups, a bitless bridle with reins attached to it that rested on Twilight’s neck, they are all black in color.

She summoned a pair of clothes for you to wear, which consisted of a white T-shirt with a black outline of a lightning bolt, and dark blue shorts. You also wore a pair of riding boots with spurs attached to them. You have a crop in your hand as well.

You saw that Twilight looked uncomfortable, “Umm . . . Anon, do I really have to w-wear . . . this?” Twilight asked nervously.

You smiled as you walked up to her, as she lowered her head to your level and you patted her head, then leaned in, “I think you look sexy as my big beautiful mare.” You whispered before blowing into her ear.

Twilight shivered as you blew into her ear, “O-okay.” Twilight said softly.

You smiled, “That’s the spirit, now Twilight, if you want to be a good riding horse, then you must follow some basic rules.” You explained making her nod in response.

“First; You must always make sure to be ready for when your rider wants to mount you.” You explained as you walked to her left side with her head following you.

“Why?”

“Because they can mount you in case they need to get away quickly or just want to have some fun, like this!” You shouted as you jumped up and landed on the saddle.

Twilight simply snorted in reaction as she was unfazed by your weight. “You forget, I’m a demigod, my love. But I'll humour you.”

Twilight went back in time and allowed you to jump on her back again. You were completely unaware of this, however. You were made to forget what had just transpired.

This time, Twilight stumbled forward a bit, before she found her balance and kept herself on all fours, as you slipped your feet into the stirrups and grabbed hold of the reins.

Twilight turned her head to look at you with an annoyed expression, “Now do you get what I mean?” You asked.

“Yeah, now I do. Thanks for that by the way.” Twilight replied sarcastically. Although, she was only playing along to keep her love happy. She was not annoyed in the least. She wanted to make him feel he was in charge, but in reality, it's her who is in charge.

“You're welcome, but you must always make sure that when your rider wants a ride, you must make sure to be ready to be mounted.” You leaned forward, “And you must also be ready for me to mount you the other way.” You whispered in a hot tone making Twilight moan slightly and nod in response.

You leaned back then patted her head, “Good girl.” You said making Twilight roll her eyes slightly.

“So what’s the next step?” Twilight asked.

“Yes, the next step is when your rider wants you to move, and they usually do this, by either swishing the reins or tapping their heels into their mounts sides.” You explained as you swished the reins, then you gently tapped Twilight’s barrel with the spurs making her gasp slightly, “There is one last way to make their mount move.” You added on.

“And what way is that?” Twilight asked while facing straight ahead. Unknown to you, she spoke in her mind. “Please let it be slapping my ass!”

You smirked as you raised your hand in the air, and swung in down slapping her huge ass making her whinny in happiness and sprint forward, “Whoa, girl! Woah!” You ordered as you pulled the reins back as Twilight stopped, but she reared up, neighed, and paws the air with her hooves.

You slowly dropped the reins as Twilight dropped down to all fours, snorted, and shook her head a few times, but she immediately blushed at what she just did and smiled sheepishly. “Heh, sorry. Let me cast a spell to make sure you are protected if you fall off me.”

Her horn lit up with a glow, and a flash hit your body. “There, you are safe now.”

“Thanks, Twily, but I think I would have been fine, I do have stirrups and I’m able to hold the reins, but better to be safe than sorry.” You replied.

Twilight nodded her head in response, “Also do riders in your world really slap their asses to get them moving?” Twilight asked with a raised eyebrow. “Not that I mind, you are free to slap my ass all you want.”

“Heheheh, well, they don’t use their bare hands, they use either a crop or whip.” You answered while scratching your cheek, slowly with one finger.

You saw Twilight’s whole face go red as she turned forward again, “Oh . . . oh, I see. I am a little worried that you could trigger a growth spurt.”

“How? By using a whip or crop?” You asked confused.

“I’m not sure. Just a theory.”

“Well in that case I won’t use a whip or crop then.” You replied as you slipped the crop you were holding into your back pocket.

Twilight giggled. “Unfortunately, I love you, Anon.”

“I love you, too, my big sexy mare,” you said softly, petting her mane. This gave her a mini growth spurt, as she gained about two inches, but due to the two of them having their moment neither of them noticed.

“And the final rule is the most important rule of the three.” You explained.

“What is it?” Twilight asked.

“It’s that you must obey me at all times. When I tug on the reins, you must follow the direction.” You tugged the reins left to the right making Twilight turn her head in the directions obediently, “Also when I tug the reins up, you must rear up.” You continued.

“Why would I need to rear up?” Twilight asked. However, in her own thoughts, she said. “I will do anything for you my love.” Despite the substantial power, and not to mention the size difference between you and her, she was more than willing to play the part of a submissive mare if it made you happy. The immortal alicorn found this roleplaying fun to do with her mortal lover.

“For fun.” You answered simply, making Twilight giggle at your response, “As well as obeying your rider you must trust your rider no matter what.” You explained in a fairly serious tone, to tell her that you're serious (Well not so serious but she doesn’t need to know that)

“Ummm . . . why must the mount obey their rider at all times?” Twilight asked.

“Because the rider steers the mount, he makes sure that they are going on the right path, the mount just has to carry their rider at all times.” You explained.

“But what if the mount doesn’t like what the rider does?” Twilight asked with a slightly scared expression, you can tell that she’s talking about you doing something that she won’t like.

You rubbed her neck making her sigh softly, “Twilight you know I would never hurt you, you know that right?” Twilight nodded at your question, “Then you should know that I only care about making sure that you won’t get hurt, as I’ve said, you must trust your rider at all times.” You explained as you continued to rub her neck.

Twilight nodded while sighing happily at your rubs. You withdrew your hand making her groan slightly at the loss, “Now that you know all of the steps, let’s see if you do good on a field practice as good as listening.” You explained with a smirk.

Twilight pretended to look offended, “My human Anon, I can be just as good on the field as well as inside.” Twilight replied in a fake offended tone.

Your smirk grew, “I’ll be the judge of that.” You said as Twilight turned forward, “Hi-ho Twilight away!” You shouted as you tapped her barrel with the spurs, causing Twilight to rear up, and neigh and paw the air with her hooves.

When she came back down she galloped around the field. You enjoyed riding Twilight around the area, it made you feel like you're back at home, but this felt better because you can talk to the mount since they listen to you and they can respond.

Once you had your fun and pulled the reins to a halt, making Twilight stop, she turned her head to look at you, as you gently stroked her muzzle with your outer palm making her lean into your touch with a happy sigh.

“I love you Anon.”

“And I love you too Twily.”

You and Twilight leaned forward as your lips connected, both of you showing the amount of love and affection for each other by this one kiss, suddenly you felt Twilight shaking underneath you as you withdrew, then she suddenly grew in size, snapping her whole riding tack off her back and face.

When the saddle snapped you fell along with it and you landed on the ground with an ‘Oomph.’ However, the pain was nullified by the spell she cast earlier.

When you looked up, you were gobsmacked because Twilight grew so large that she’s basically the size of an elephant at the very least in your world, if not even greater. Perhaps, several times the size of one. Twilight was now so tall that she was basically a giraffe. She must have been at least 20 feet tall. Her former beachball-like buttcheeks were almost hot air balloon-like in appearance at this point. You were pretty sure you no longer had a big enough dick for this extra-large mare now.

The weight of her hooves pressed down hard on the earth below. Her hooves sank into the dirt deeply from her tremendous weight. You were glad Twilight seemed to have weight protection magic, otherwise, this super heavy pony would be dangerous to approach. You were not intimidated in the least, Twilight was a gentle giant mare.

Twilight smiled sheepishly, her face blushing profusely as she looked back at you. “Oh, sorry about that. Do you want me to shrink myself back down again?”

You stumbled onto your feet and voiced your objection. “Twilight. You’re as big as a house! A big sexy house.”

“Hehehe! You want this big butt?” the mare giggled with a hoof over her mouth, and began to shake her massive, jiggly rump from side to side. This created a thunderous clapping sound as her gargantuan buttcheek slapped against one another with loud, meaty slapping sounds of flesh slapping against flesh. This had the added consequence of her massive, beach-ball-like crotch-tits slapping each other, creating additional meaty slapping sounds. A river of marecum was flowing out of her marehood, creating a pool of her creamy essence underneath her.

As Twilight continued to shake her ass from side to side. She lifted one of her front right hooves, and reached back to her huge backside, and pressed it against her right cutie mark. You watched in delight as her heavy hoof sank into the plush softness of her ass, her hoof’s applied pressure created a deep depression upon her buttcheek. She held her hoof there for a good few seconds before releasing it. Subsequently her cheek soon resumed its perfectly smooth shape when she pulled her hoof away.

“You're one big sexy mare!” you shouted, raising your hands in praise.

Twilight giggled, before dropping her ass hard down upon the ground below, this created a deep crater in the earth from the heavy impact of her massive backside. “You wanna make this mare even bigger by cumming between my cheeks?”

Twilight’s buttcheeks were now so wide, you could be encased by the bubbly softness of her ass on either side. Before you could venture forth and cum inside her however you heard a pair of flapping wings from behind you.

Twilight gasped in shock, and shrank back down to 7 feet tall with a flash from her horn. “Princess Celestia?! What are you doing here?”

You turned around to see it was indeed Princess Celestia. She had a bemused smile on her face.

“I see Anon showed you the magic of friendship. But can I have the magic of friendship too?” she said, making to land before you.

Twilight made to stand up, and turned around to hide her cum drenched backside. “I don’t think it will work. He tried cumming inside Pinkie Pie before we went out, and nothing happened.”

Celestia uttered a low whimper. Tears began to fall down her cheeks. “Butt….. Butt….. Butt… Butt… I had the biggest butt? Who will think of me as a leader if my butt is smaller than yours?” she said in a low voice, looking at the taller alicorn before her.

“What is it with you ponies and your obsession with butts? Get over yourself, Princess Celestia. You still have a lovely fat ass, I will gladly fuck it.”

“But Twilight’s butt is bigger…. and it grows bigger when you cum inside it. How am I supposed to compete with that? What if all my royal guards turn on me and mount Twilight instead of me? Now, I know exactly how Luna feels with a smaller butt.”

Twilight spread out her wings. “Nobody is allowed to mount me from behind, other than Anon. I am his faithful steed. I will need Anon’s help if some evil shows up. I will need him to cum inside me so I can face the next villain, and facesit on them into submission. They will struggle to lift my magnificent backside to no avail, I will only lift my massive butt off their face when they change their ways and reform.”

“Oh, Twilight. I’m so sorry! I can’t stay mad at you! Not with such a wonderful ass to keep Equestria safe from evil!” she shouted, she made to trot around her, and embrace her ass, and bury her face between her buttcheeks. Her hooves sank into the plush softness of Twilight’s bountiful backside. You joined Celestia and placed your hands on Twilight's right buttcheek. Your hands sank into the squishy softness of Twilight’s backside.

You were pretty sure you were going to have many big booty adventures with Twilight. But right now, you just wanted to embrace her ass alongside Celestia during this tender butt moment.