Author's Notes:

This chapter idea was requested by Jaybird78, and is a clop scene featuring themes such as hyper-endowment, big penis humiliation, and massive amounts of cum. Reader discretion is advised.

If you want to see something more atune to your own liking, then I recommend you check out my Patreon and consider being a Patron. All ideas are welcome (with obvious exceptions), and I update the story each month with chapters based on Patron prompts.

It had been over a week since the Surveillance spell was previously used, or since the room had even been entered by any of the three spellmages. That may have not been that long of a break in time (at least in comparison to some of the other countless rooms within the castle, which were usually left unused for months at a time), but it still felt rather long by the time the Alicorn and her student returned. Even though Twilight and Starlight’s weekend of research ended up being fruitless, neither of them tried to dwell too hard about it by the time they decided to return to their work. However, despite not wanting to question the capabilities of their controversially-used magic, both of them looked surprised when they saw that the glowing, hovering orb remained just as it was before.

“Wow!” blurted Starlight with both brows raised as she entered the room first, and Twilight locked the door behind them. “I’m not gonna lie, I would’ve figured the magic would wean off over time without any usage. Especially without any magically-infused items to maintain its structure.”

Even though she agreed with her protègè on the matter, Twilight gave a brief shrug before she explained, “Well, the spell actually is working non-stop. Technically speaking, the magic infused within that dome is constantly pilfering out, and able to detect any events that can trigger its emotional sensors. However, it doesn’t necessarily focus or record any of those until it’s activated by one of us.”

Starlight couldn’t help skewing her muzzle in uncertainty from learning that detail. While the Princess sat herself down on the couch, her student glanced back at her worriedly and asked, “Uhhh… is that really a smart idea? I mean, I know we’re already bordering ethical lines with this research, but it seems a little shady knowing this thing is constantly spying on everyone in Equestria.”

Twilight sighed with a pursed muzzle when she took notice of Starlight’s apprehension, and gave an understanding nod of her head. “Well… I suppose I can understand interpreting the spell in such a way,” she replied while trying not to sound too discomforted by the mare’s viewpoint. “However, I just want to reiterate that it’s not recording anything without any additional magic interference. It’s mostly just… listening in without being able to pay attention, if that makes sense.”

“Honestly, it kinda doesn’t,” said Starlight as her expression turned more wary. After a brief huff, she sat down beside her mentor on the couch and asked, “I mean, how do we know it’s not recording everything without us interfering? Because given our situation, I’m a little worried about using this spell when we’re still unaware of how to fully control it.”

Twilight looked away from her as she sighed and bit her lip; unfortunately it was unclear whether her expression was due to her feeling dismissive about her student’s point, or a little worried herself. Starlight then pointed towards the orb before them and added, “Like, isn’t it a little worrying that this spell is still running without either of us maintaining it?! I mean, I know I shouldn’t be getting too paranoid on the matter, but I don’t think you can blame me for acknowledging that fact!”

“I’m not, Starlight,” the Princess said as she pointed at her with a hoof, and shot her an insistent stare. “Believe me, the last thing I would ever want is to allow an untested spell to go awry. And given how we’ve both dealt with controversial magic throughout our lives, I can probably understand your worries on the matter better than most other ponies.”

Starlight kept her muzzle shut as she processed her mentor’s points, and nodded her head back towards her. But before she could try to say anything else, the unicorn could only listen as Twilight continued with a motion towards the dome, “But in regards to your thoughts about us not being able to control this magic, both Sunburst and I have ensured that it could easily be turned off at a moment’s notice. The only reason we haven’t done so yet is because of how complex its original conjuring was. Not to mention, all of our recordings are connected to the orb like a hive mind. If we turned off the spell now, then all of our research might be compromised as well.”

Starlight looked like she wanted to say something else on the matter, or even bring up how dangerous it could be to leave it running for anypony to find. Despite how hidden the room may have been, the student felt compelled to mention, “Well… considering what happened the last time some psycho discovered magic like this in a hidden place, I’d rather not deal with that again with this spell.”

Twilight instantly winced as she nodded back at her, not needing to clarify what Starlight was referring to. While she hated to think of a spell like this could be used negatively, she could only imagine how someone like Chrysalis or Cozy Glow could manipulate it to their own twisted whims. She looked away from Starlight while thinking over that fact, and skewed her muzzle before coming to a logical conclusion.

“Well… Alright, that’s a very hard point to try and debate, Starlight.” She then exhaled sharply as she glanced back at her, and said, “You know what? As soon as we finish our work today, I’ll write to Sunburst to see if we can have a failsafe for all three of us. I know of a process that can use crystals to connect with the effects of certain spells, and I know for a fact that he could assist us with implementing that method for this.”

“Sooooo… what would that necessarily mean?” Starlight asked in clarification, even though her tone seemed rather optimistic due to the Princess’ confident expression.

“It just means that if we can connect this spell to a crystal for each of us,” Twilight explained while motioning over towards the orb, “then we’d all have a means to break the spell in an instant. If anything goes wrong, one of us could just break our crystal and destroy it without hesitation. No harm, no foul.”

Starlight’s brows rose in surprise upon hearing of such a technique, but she also smiled gratefully as she nodded her head. “That… That would be really comforting for me,” she said in a kind and grateful tone. “Thanks.”

“No problem,” assured the Alicorn with a smile of her own. She then shook her head with a huff as she looked back at that floating orb, and lit up her horn cautiously. “Honestly, I think Sunburst and I were both contemplating having an option like that just in case. But given your points, it might be best to try it sooner than later.”

She then gave that orb a quick zap with her magic, which caused the magic within to stir and activate with that familiar multicolor glow. While the floating array of spells churned and awakened before the two, Starlight stared at it cautiously while trying not to shudder. “Yeah, no doubt…”

While she may have not felt much worry about that magic orb prior to all of their wasted research, Starlight couldn’t help but grow nervous about its capabilities now. But regardless of her own feelings on the matter, she tried not to focus on her own thoughts as a new screen began to conjure within its glowing state. Twilight seemed more optimistic about re-starting their research, but it wasn’t long before both of the mares’ expressions turned confused. The moment a scene started to show within that screen, the two were met with the sight of two unexpected acquaintances; one was a student of their school, and the other was one of the recently-revived Pillars…

“Oh, come ooooonnnnnn!~” Yona carried a strong pout on her face as she eyed the skinny pony with a pleading look. “Pleeeeaaassse, Mister Stygian? Yak promise that nopony will know.”

Despite the yak’s insistent tone of voice, or her reassuring stare as she crossed her hoof over her thick chest, Stygian seemed more than a little hesitant to comply. The grey stallion may have looked rather meek in stature (especially in comparison to Yona’s bulbous build), but he tried to stay firm as he answered with an honest-sounding, “L-Listen, I… I really do appreciate your curiosity on the matter. And I really mean that. But, ummm…”

Stygian’s muzzle contorted worriedly as he glanced around the open space he and the student were in. The two were seated at a vacant picnic table behind the School of Friendship, which happened to be the furthest away from any windows. While the area may have not been the most isolated, both Twilight and Starlight were aware that it was one of the better places to be alone while on school grounds. But regardless of that fact, Stygian exhaled through his nostrils before he turned his attention back towards Yona. “Y-You know, I… I could get in some serious trouble if either of us were to get caught doing this.”

That remark made both of the mares watching turn worried in an instant. Meanwhile through the screen, Yona just huffed with a carefree wave of her hoof. “Oh, don’t be such a baby!~” she jeered while eyeing him playfully. “School is off today, remember? Most students are off campus, and yak made sure that we were alone. Besides, it’s just an experiment, remember?~”

The yak gave a cheekier-looking grin as she perked up her brows a couple times, seemingly trying to coax him into agreeing through her charms. Unfortunately, Stygian didn’t seem to be comforted by that assurance, and continued to look around the open space in reluctance. Back through the other end of the screen, Twilight already had her horn lit in case she needed to teleport in and stop whatever might happen next. However, Starlight made sure to tap her on the shoulder and remind her, “Hey, Yona is a legal adult, isn’t she?”

While that fact may have been true, the Princess still shot a warning glare back towards her. Meanwhile, both of them could hear the yak assure him even further with a truthful, “Stygian, yak promise if any ponies see us, I’ll take full responsibility. I even know Pinkie Promise if that helps~”

Stygian sighed as he tried to avoid looking back at her, and pursed his lips in contemplation. “Honestly, I… I’m a little surprised you’re so interested in seeing it,” he muttered nervously. While the stallion tried to hide his face behind his thick blue bangs, Yona just stared at him with a bewildered look.

“Are you kidding?!” she gawked while trying not to chuckle in amusement. “Yak would LOVE to see it up-close! You have any idea how hard it is for a pony to impress yaks like that?! You could be legend!~”

The pony let out a weak giggle while his freckled cheeks began to blush. “W-Well, I… I already kinda am a legend, heh heh…”

“You know what yak mean,” Yona said firmly, before she grew a more studious grin and leaned in close to Stygian’s face. Her eyes narrowed on him while she looked up and down his gangly form, and took a second before speaking in an enticed tone. “If you let me see for one minute, then I won’t ask you any more. Yak swear~”

Stygian took several seconds to think over the yak’s offer, and whinnied in hesitance while looking away from her. But before the Princess watching the two could try and stop Yona’s offer from being fulfilled, Stygian sighed in defeat before lighting up his horn. “If… If you really mean that, then… I suppose I can let you see for a moment…”

The stallion closed his eyes while his head was pointed downward, and a strong surge of his brightly-lit magic shot out to send a magical stream directly towards his crotch. Yona scooted back in her seat at the table as she watched intently, and clapped her hooves excitedly while grinning ear-to-ear. Stygian let out a sharp gasp the instant he let that magic strike him in such a tender area, and his body convulsed wildly as a profound change occurred between his legs.

While Yona’s eyes lit up excitedly, Stygian groaned in a mix of sensitivity and pleasure as his stallionhood grew out at an absurdly wild rate. The stallion’s cock inflated outward like a balloon, and expanded to a size that nearly rivaled the rest of his body. The unicorn may have been fairly meek and timid in stature, but his cock looked absolutely gargantuan as it was exposed in all of its throbbing, veiny glory for the lone yak to see. Just beneath that scarily huge member, Stygian’s balls were swollen out to the size of bean-bag chairs as they draped over the bench of the table, and nearly touched the grass below from their daunting weight. By the time his concealing spell was undone, and the pony was left wincing with a bit lip upon being exposed so blatantly, his penis was towering over his head as it stood with a length of over five feet, and a girth of at least three feet in circumference.

Yona seemed beyond satisfied with the sight as she marveled at that monstrously oversized cock up-close, and her smile was hung-open beneath the stars twinkling in her eyes. Meanwhile, Twilight and Starlight could only stare at Stygian’s equipment in absolute shock while their jaws were hung wide-open. Even though it was likely that any pony would’ve had the same reaction to that as they did, the two scholars learned enough about controversial spellmaging to know exactly what the stallion may have done during his teenage years. Since the practice of ‘body alteration spells’ was beyond taboo in most unicorn households, Twilight could only mutter after overcoming her stunned silence, “I… I thought that stallions expanding their penis size was only a legend.”

Unfortunately, the only words that Starlight could reply with were, “HOLY… BUCKING… SHIT.”

Despite the mare’s inappropriate language in front of Royalty, the Princess could only shrug in silent agreement while their eyes were glued to the screen.

“Oh… Oh, WOW!!~” beamed Yona through the other end of that magic feed, as her cheeks blushed to a heavy shade of crimson. She blinked a couple times as she stared at the bashful stallion’s oversized cock before saying, “Yak knew that unicorns had skills, but THAT’S really cool!~”

Stygian nervously chuckled while avoiding the yak’s enamored gaze, as well as his massive cock that was twitching readily between their bodies. “Uhhh… Heh heh heh… W-Well, it’s not like all unicorns my age did that,” he muttered with a hint of shame in his tone. “It… It was actually a huge detriment to my work, a-and… it’s a big reason why I use concealment spells to keep it regularly-sized.”

Yona may have not had any personal experience with a penis to understand the stallion’s dilemma, but she still nodded sympathetically while peering in closer towards that gargantuan appendage. “Yeah, yak bet,” she said while smirking a little, and using her hoof to poke the veiny beast playfully. “Could you even walk while having it like this?~”

Stygian briefly grimaced with his muzzle wrinkled with a blush, looking embarrassed by such a question. But alas, the stallion could only sigh before saying, “I, uhhh… I couldn’t walk easily…”

Yona’s smile became slyer as she got in even closer, and let out a faint shiver when she caught the profound musk wafting from Stygian’s massive member. Before the unicorn could stop her, she brought her other hoof out so she could grasp that gigantic shaft more firmly. “Mnnnghhh… no wonder you had to hide this~” she growled as her tone turned most lustrous, and Stygian was left unable to stop her while his sensitive shaft was being gripped so hard by her brute strength. While the stallion groaned in surprise and reeled his head back, the antsy yak pressed her snout in against his pulsating cockhead to get a strong whiff.

“GnnnNNNNnnghhhh~” She instantly sighed with a blissful moan the instant her senses were hit by that heavy wall of musk, and her drooling muzzle hung open while she quivered before Stygian’s cock. It was obvious that the yak was wanting to indulge in his equipment, and didn’t try to be subtle on the matter as she brought her tongue out. After giving the underside of that gigantic stallionhood a long, lingering lick, Yona moaned even deeper from the profound bitter taste that soaked into her tongue. “Aaaahhhh!!~ Y… Y-Yak bet you never had a mare give you that, huh?~ Wi… With how big this thing is, you’d probably scare off any ponies who saw it~”

Stygian’s face was scrunched inward with a look of humiliation, and he could only respond with a strained groan before Yona gave his cock another hearty lick. Twilight and Starlight were too stunned by the display to do anything from their end, and could only watch as a massive dollop of precum spurted out from the stallion’s leaky tip. The bulb of milky-white pre oozed down from the crowned tip, and looked large enough in volume to overfill a measuring cup with his seed. But for the horny yak holding his cock like an oversized toy, she didn’t look the least-bit intimidated as she leaned her muzzle up towards it, and sunk her lips within that glob to suck up a muzzlefull. Her body squirmed wildly as she made an enthusiastic gulp of that glob of pre, and she pulled back with another sharp exhale while her mouth was coated in the glossy substance. “Mnnnghhh~ Oh, man!~ You lucky you have yak to service cock this big, Stygian. Because I doubt any ponies would wanna be around it for too long~”

Stygian moaned out direly as he sat back with his teeth gritted, unable to counteract any of Yona’s teasing statements. Meanwhile, the yak went back to rubbing her hooves up and down the unicorn’s throbbing shaft, and tasting more of that thick cockhead with her tongue. She also dragged her muzzle along the stallion’s massive crowned-ridge, and nibbled the flesh hard enough to leave him writhing in pained pleasure on the bench. With each teasing bite or lick Yona gave, heavy spurts of precum shot out to hit the yak’s thick coat. But despite how messily the fur around her face was becoming matted with Stygian’s loads, her enamored blush still shone through while she kept speaking mockingly up at him. “Heh~ Yak bet you never got any girls to touch you like this, huh?~”

“Nnnnnffff!!~” Despite how insulting that assumption may have sounded from the mares watching in shock, Stygian could only moan out needily and shake his head. Due to Yona’s continuous licks and nibbles, he had to take several heavy breaths between moans before he could answer her. “Aaaahhh!!~ I… I… I h-h-haven’t…”

Yona smirked confidently after hearing that reply, and pulled her head back while a couple heavy strings of pre connected her fur to Stygian’s cockhead. She made sure that the stallion was able to look back towards her before she locked eyes with him, and made a teasingly arousing lick around her muzzle to catch a good portion of his precum. She then gave a cheeky wink before closing her muzzle shut, and making an audible gulp of his seed. Since Stygian could see the hefty bulge that traveled down the yak’s neck from that swallow, he squirmed hard in front of her as he leaned back and struggled not to cum right there.

Meanwhile through the other end of that magic feed, Starlight grimaced a little as she clenched her hind-legs shut, and kept her sights solely on that screen as to avoid any awkward stares back towards Twilight. Fortunately, the Princess was looking equally as flustered as she sat with her muzzle clenched shut, and her face burning hotly from her blush. Neither of them wanted to acknowledge the other while they watched such a… controversial scene unfolding, but it didn’t seem like either was willing to try and stop the recording either. Instead, the uncomfortable silence between them only grew while they watched Yona pumping Stygian’s monstrous shaft with both hooves.

“Aaaahhh!!~” The yak couldn’t help moaning as she tried her hardest to jerk Stygian off, even though her forelegs were too short to really bend appropriately. Instead, Yona had to move her whole body up and down as she grinded against the stallion’s shaft, which only made her grow more pent-up with each motion she made. The thick tufts of fur between her hind-legs were beginning to glisten from her arousal, and were dripping onto the bench below her. While her stretched-out cunny tried to convulse in need for attention, Yona stared up at the timid stallion with serious bedroom eyes as she literally rode his cock out in the open.

“Y… Your cock might not be suitable for any ponies, Mister Stygian,” she purred with a wide and teasing grin, which caused Stygian to wince with his teeth tightly gritted. Meanwhile, the yak moaned out briefly as she dragged her tongue along the rim of Stygian’s urethra, and licked up another messy glob of precum to swallow without hesitation. After licking off the substance from her glossy lips with a satisfied groan, the yak pulled herself up so she could tower over that massive cock and grin in determination. “However… that monster cock might be good enough to satisfy yak like myself~”

Before the unicorn could even think to protest Yona’s impulsive advance, she managed to get her whole body latched against the underside of his cock like a horny sloth gripping a tree-branch. Her rear hooves pressed down hard against his massive balls, but she thankfully wasn’t heavy enough to cause too much pain as those hefty orbs continued to pulsate readily. The unicorn still winced in pain from Yona’s immense weight against him, but the girth of his erection proved to be just as strong as its size. Because of that, the pony could only let out a strained moan when he heard the yak say while grinding against his shaft, “Aaaahhhh!!~ Si… S-Since you’re too big to satisfy any mares, y… y-yak will allow you to use this pussy~”

Yona emphasized her readiness as she continued to grind her gaping pussy against his cock, which caused small rivulets of her arousal to dribble down his shaft. Her breaths turned more rapid as she squirmed harder against him, and bent her head down to keep teasing his cockhead. Fortunately for the two, Stygian’s needy moans beneath her embrace weren’t loud enough to warrant any unneeded attention their way. Or to be more specific, no unwarranted attention that would be willing to stop them from continuing.

Yona was growing a deeper blush with each thrust of her hips against Stygian’s shaft, and was clearly growing more pent-up as the second passed. Meanwhile, Stygian’s cock spurted out more heavy ropes of his precum, which drizzled across the yak’s chest and face to leave her more glazed than before. Of course, it was doubtful Yona minded in the slightest as she grinned eagerly, and shivered from the titillation she was giving herself. “If… If you agree to let yak bring you back to my dorm room, th-then… then I’ll let you fuck me with no condom!~”

Stygian tensed up immensely as he moaned underneath her weight, and spurted out a rope of pre hard enough to shoot over her head to land across her back. “Nnnnnghhhh!!~ Bu… B-But I--”

“No ‘Buts,’ pony-boy~” she growled while keeping the unicorn on edge with her motions, and making his cock more drenched in her budding arousal. “If y… If you want to give a girl pleasure with that thing, th-then you have to take what you can get!~ E-Either take my offer, o-or… or try to find another girl willing to use that monster cock of yours!~”

Even with the looming worry of impregnation plastered across his mind, it didn’t take long for Stygian to give in to the yak’s intimidation. With his gigantic cock experiencing such an intense bout of pleasure, the unicorn’s mindset was too clouded in lust to really think over the ramifications. Instead, the pony could only moan out in unrelenting need as he squirmed underneath the horny yak and cried out, “A-ALRIGHT, ALRIGHT!!~ I… I’ll do it! I-I’ll have sex with you, I swear!~ J-Just PLEASE get off before I cu--UUUUUHHHHHHH!!!~”

Before Stygian could say another word, Yona’s efforts seemed to have been a little too effective. The yak couldn’t even move from her spot before she felt his balls churning hard beneath her hooves, and she felt a rumbling throb while that shaft was tightly pressed against her chest. The unicorn couldn’t hold it in anymore, and he cried out in utter rapture as he came.

Stygian’s load shot out with a ferocity unseen by any pony in his current timeline, and the sheer volume of his gushing cum was hefty enough to leave Yona (as well as Twilight and Starlight) completely speechless. Like a broken levee in a dam, the pony’s oversized cumshot erupted as gallons of his jizz rained down over both of the moaning creatures’ bodies. Yona was taken aback as the pony’s hot and heavy load drenched over her writhing body, and she was caught underneath the musky stream without any salvation. Fortunately, despite how much Stygian groaned in shameful remorse from cumming prematurely (especially out in a public space without any protection), the yak was taking that cum-shower in much higher stride as she moaned and convulsed against his throbbing shaft.

It may have not been a proper impregnation (yet~), but Yona still came hard as she embraced the overzealous bukkake that would’ve made the biggest size-queens squirm in envy. Her coat was growing heavier as it soaked up as much of Stygian’s cum as possible, and her stretched-out pussy gushed like mad between her stubby legs. Her eyes clenched shut while she cried out in bliss from the overwhelming sensations, and didn’t seem embarrassed at all from being caught up in such a provocative state outdoors. In fact, it seemed like the yak was downright relishing in that fact as her moan lingered on, and her orgasm lasted longer than Stygian’s oversized cumshot.

Just as the screen began to fade away within the magical orb, Twilight and Starlight were left with the ungodly sight of Yona completely soaked in Stygian’s cum, and the poor stallion left exhausted beneath all that weight while moaning tiredly. But before they could hear either of the two say anything else from the aftermath of their session, Twilight shivered uncomfortably and exited the room without a second of hesitation. Starlight was too stunned by what she witnessed to pay much attention to the recording, and just remained on the couch by the time that scene finally disappeared from sight.

The lone unicorn blinked a couple of times as she processed everything in silence, and eventually said in a brief murmur, “Ummmm… so… that happened, I guess…”