It was Ben's favorite day of the week at Bellview Jr. High, Chili day and the 10 year old sometimes superhero, most of the time doofus had wolfed down 4 bowls of the stuff, getting looks of wonder and disgust from his classmates and a sneer of digest from Gwen.
"Jeez, can you even taste it with how fast your eating it?" Gwen asked, shaking her head. "you know when you eat too fast you get gas, and your always bad after chilli." She added, shuddering in horror from the memories of sharing the rust bucket with Ben when grandpa  had stopped at a chilli festival.  "Stink fly smelled better then you did." 
"I know your trying to shame me and make me slow down or stop.." Ben said, pausing from licking his bowl clean and having chilli on his chin, then he let out a LOUD belch and grinned proudly before adding. "But I consider that a achievement, and look forward to topping it!"
"Ugh.. I'm SO glad I don't have any classes with you.." Gwen said, holding her nose and getting up from the table, her own bowl of chilli only half eaten, Ben had unsurprisingly made her lose her appetite.
"Hey, if your not gonna finish that.." he called to her and she rolled her eyes and slid the bowl over.
"Have fun stinking up the school. I hope you crap yourself." Gwen said, and took off, not knowing how foretelling her words would prove to be.

Charmcaster, having broken out of jail earlier in the week and looking for revenge on Ben (Since during their last fight he had farted in her face after turning back to human) had snuck into the school before lunch had been started and using a simple invisibly spell had added a little bit of this and a little bit of that to all the chilli, making sure that anyone who had some was going to be in for a rough time for the rest of the day.
But that was just step one in operation revenge is best served stinky (the name could use work, she'd be the first to admit that but it worked) Step two and three was where the real evil came into play. A bit of magic teleportation used on the boys and girls restrooms, and replacing certain items in the school infirmary would ensure Ben would never, ever forget this day. 
Still, as she watched him chow down, she had to admit it was stroke of luck he was such a greedy little pig, it would only make what was about to happen look more au natuteral.
Or how ever the french said it.
'I think learning Latin for half of these spells was more then enough..'

Unsurprisingly, most of the other kid kept a semi distance from Ben as he made his way out onto the schoolyard, those who hadn't seen him pig out had heard tales and it was a common belief that he was a ticking time bomb waiting to go off. 
even his bullies were standing back, Cash having gone to wedgie Ben once before on chilli day and having gotten a fart attack in retaliation that had left him gagging and tears leaking down his cheeks.
Feeling a tad bloated and belching off and on, Ben went for a little stroll to work off his lunch, though he noted as he walked around the school yard that more then a few of the other kids were wearing looks of discomfort and he wasn't the only gassy kid.
"heh, must of been a semi bad batch." Ben mused out loud, feeling a poot building up and looking around to make sure no one was too close. "And Gwen acted like I was just a pig.. welp, time to let this birdie fly!"
Bending down like he was looking at a flower, Ben gave a soft grunt and let a massive wetish fart rip, and started to smile, it just felt so good to let out and he didn't care that it had been SO loud that yeah, other kids were turning in his direction. 
At least he was enjoying it till it stopped being a fart and suddenly he was filling the seat of his pants with a hot mush that came out with zero control from Ben, his butt was clearly ignoring any and all orders from his brain to stop and 'close the hatch' so to speak.
'Maybe I'll get lucky and it's NOT noticeable..' Ben thought, his cheeks turning crimson as his undies puffed out, a hope that was quickly dashed as he heard a cry ring out from a girl in his class.
"OH MY GOD! BEN'S CRAPPING HIMSELF! LOOK AT THE BACK OF HIS PANTS!" She yelled, voice filled with mirth and laughing after she spoke, and yeah, soon other kids where crying out, pointing and laughing at Ben who found himself unable to stop, or get up.
he was stuck in the poopers position till the 'ride' was over.
"Oh wow, look at the lump!" a boy called, out, a mix of grossed out and fascination.
"Ewww it's leaking though his pants!" A girl said, clearly disgusted.
"Thank god the wind is blowing in the other direction!" A girl said with a valley girl accent, Ben didn't dare turn around to confirm who was speaking after all.
"Hey Tennyson, did you forget to wear your huggies?" Came the taunt from Cash, a voice Ben knew far too well to mistake.
"Children! that's enough!" Scolded a male teacher, Mr.woods if Ben wasn't mistaken. "Clearly Ben had a bit too much. Now back off while I go get the poor little guy inside." 
Ben huffed at being called a little guy, but as his smelly load slowed and stopped and he went to stand up on shaky legs, he was glad for the kind teachers words, and for his support as Ben had to semi lean on him.
Hopefully, the school nurse would be just as kind and understanding.

"Oh my GOD, shitting your pants at your age?!? This is why I transferred out of the elementary school!" the young blond nurse asked, a well manicured hand going up to her face as she pinched her nose shut and used the magazine that she had been reading and was still in her other hand to try and fan the awful stench coming off of Ben away. 
'And so much for kind and caring..' Ben thought dryly.
"Miss Hardworm, One would think that your training included being sensitive to students in a time of stress." Mr.wood's said, a hard edge to his voice.
"Uh.. well yeah.. there was..but..come on! he's 10 years old and in 5th grade! ugh.. i knew the school made a mistake when it moved the fifth graders over here.." Hardworm whined.
"if your QUITE done.." Mr.woods said, his tone making it clear that yes was the only answer. "Ben needs to make use of your shower AND needs a check up." 
"Yeah yeah.. Ok.. Shower is that way.. there's a plastic bag in there for you -gag- pants and underwear." Hardwood said, setting the magazine down to jerk a thumb in the direction of the small shower room she had just behind her desk. 
"Truly, you are a overwhelming cup of kindness." Ben said, rolling his eyes and waddling past her (waddling from the load in his pants of course) and making sure to get a little bit extra close to her so she'd jump back.
"Did you see that!?!" she cried out to mr. wood's as Ben closed the door behind him. 

While Ben showered and made use of the potty in the shower room to make sure he was all done, other kids in the school weren't feeling so hot and a wave of poots were escalating all around, at least with anyone who'd had the chilli. Charmcaster took this all in with a smirk and a grimace, as while she was unseen and unheard, she couldn't block off the smell and made a mental note that next time she planned something like this, she'd bring nose plugs.
A loud and massive poot from a chubby kid close to Charmcaster almost had her blow her cover as she had to cover her mouth not to loudly gag, and she dashed off, making a small change in her plan to be outside of the room when the next parts of her plan kicked in.

Positive that the tank was running on fumes, Ben walked out of the shower room with a towel around his waist and his t-0shirt back on, his undies and pants triple bagged and a couple of bars of soap tossed in for good measure.
"Sooo uhh.. Where's the spare undies and pants?" Ben asked, looking at Hardworm and semi worried because Mr. wood's was no longer there. 
the blond gave Ben a nasty smile and then in a tone that did nothing to hide her delight, started to speak while holding up a short, pink Tutu.
"Well as it turns out, we don't have ANY spare undies at ALL in here! Shocking huh? Guess they figured that you know..big boys and girls wouldn't be crapping their pants! as for pants.. this was ALL I could find in the lost and found, it's not much but it'll cover up the DIAPER I'll have to put you in anyways~" 
"..Heh..OK..I must still have water in my ears, But I could of swore you just said.. you have to put a DIAPER on me." Ben said. Blushing and giving a nervous smile."Buttt seee, that CAN'T be what I heard because that's just crazy right?...RIGHT!?!" Ben said, a panicked tone taking over and then in a small pleading tone he added. "Right?"
Nurse Hardworm just smiled wider and set the tutu down, and pulled out a thick, grey and purple diaper with pink tapes. "What do you think? and look, we even got new diapers in JUST for little pants poopers like you~ Little charmy's they're called." she said with a nasty tone in her voice, following up with a laugh and then walking over and patting one of the beds for kids to lay on. "Hop up widdle guy~" 
"..And to think..I thought crapping myself was gonna be the worse part of my day." Ben whimpered.
"The days still young." Hardworm snickered.
Ben groaned and slowly shuffled over, dropping the towel from around his waist as he slid onto the bed, and covered his eyes. 
'this can't get ANY more humiliating..' he thought to himself, only to have Hardworm giggle and lift up his shirt and tickle his tummy.
"Awww, who's a shy widdle guy? you are! it's ok widdle man, Nurse Hardworm is here to wook after you!" She coo'ed, her tone taking on a motherly tone  and as Ben peeked from behind one of his hands, she was legibility giving a nice smile.
'Just had to tempt fate didn't you Benny?' he mentally groaned.

For the next minute or so, Nurse Hardworm was kind and gentle, coo'ing softly and baby talking to Ben like he was just a toddler as she got the diaper under his butt and powdered him up, then tapped it nice and tight and helped him to his feet, giving his rump a soft pat.
"There you go little guy! I guess we can skip the tutu..If you hurry you might be able to go and get your gym shorts and slide them over your diapey wipey!" She coo'ed and tickled his chin.
'Geez, maybe she isn't such a hard ass after all..' Ben thought, giggling a little and starting to smile. "That sounds great!"
"Good..now get out of here you little shit before you crap yourself." she said, the nice act gone just as suddenly as it had appeared.
"...you have a split personality or something?" Ben asked, raising a eyebrow.
"Look, seeing you all helpless and needing a diaper..brought out a part of me that I try and keep buried and you'll be buried too if you tell anyone." she said and jabbed a finger into his chest.
"..Rest assure, I doubt ANYONE will ever mistake you for a beacon of kindness." Ben said, rolling his eyes and turning to leave. 
Looking out into the halls, they were mostly deserted, save for the hints of a long line up waiting to use the bathrooms, Ben could see the back half of a kid from the window in the door. 
'Huh, guess the chilli hit everyone hard..' Ben thought and went to turn the door knob. 

Charmcaster was peeking in though the window, still invisible but knowing that any second now her little spell for stage two was about to kick in as the first wave of boys and girls would be about to flush the potties in the rest rooms.  at which point, stage three would kick in with the diaper she had placed in there as all of the filth that was suppose to go down the drain, would end up in the back of Benny's diaper that was enchanted to expand as much as needed while doing nothing to mask the smell.
'huh.. mental note.. next time I do this.. nose plugs AND bring some popcorn for the show.' Charmcaster thought, sitting on her broom and getting comfy.

the wonderful side effect of Charmcaster's spell (Unintended but damn it worked out) was that as the back of Ben's diaper suddenly started to bloat out as it filled up, a thunderous wet farting noise was heard so it would seem like Ben was just crapping himself again. 
"oh my god, are you.." Hardworm started to ask, then put her hands over her mouth and nose. "Jesus! what are you, 90 percent bowels!?"
"I-I..I'm not.." Ben tried to stammer out as the icky muddy gross feeling spread throughout the back of the diaper, making it balloon out like a cartoon diaper would and the back of the diaper was soon down to his knee caps, even as tears started to stream down his face.
"Your not what? shitting yourself!?!" Hardworm called out, almost having to shout over the thunderous roars that was the farting sound effect as more of the waste piled in. "Bullshit!"
As the back started to get too crowded, the front of the diaper raced to match the back as Ben squealed out, from the gross feeling but well it would just look and sound like he was reacting to the jaw dropping dump he was taking. 
Already the stench was heavy in the air, making both his and Hardworm's eyes water, and Ben held his own nose with a whimper of "STINKY!" that again, did nothing to help the illusion they he was just a diaper shitting big baby.
"oh God! there's no way in HELL I'm changing that you gross little fuck! Get out of here with your shit swelled diaper before it's too big to fit though the door!" Hardworm cried out, summoning hidden depths of strength to over come the stench and the site.. to Push Ben who's diaper was almost too big out the door and make him land on his hands and knee's in the hall, slamming the door behind him and locking it for good measure.
with Ben Out of her infirmary, she raced over to the window, not knowing that a young witch had been watching the show and laughing her ass, and opened it and stuck her head out desperate for fresh air.
Charmcaster yelped and flew away on her broom, not wanting to get even a whiff of what had to be toxic stink by this point, and made a mental note that she would have to use this spell again sometime.. if not on Ben then maybe on Gwen. 

Meanwhile out in the hall Ben quickly drew attention as his farts echoed loudly in the halls and even as they died down as the last of the flushing happened, for the moment at least. 
with the massive diaper bloated out behind him, Ben couldn't even get to his feet and any and all attempts to crawl away were futile.
As students and teachers alike took in the site and taunts began to be tossed out, Ben started to laugh and cry, adding his own puny (By comparison) poopie to the load and then started to suck his thumb, the humiliation was just too much and his big boy mind shut down and went bye bye. 
Almost no one dared to get too close as the smell was overpowering, Mr. Wood's had attempted to but by then anther round of flushing in the bathrooms had started and so Ben's diaper started to grow again.

It was Gwen who figured out what had happened in the end, though there was no way to explain it out really to the world at large. Ben's mega load made news on all the stations, and he was world famous as the incredible diaper filler. 
In a act of semi Mercy, Gwen not only took the Omimatrix from Ben so that he wouldn't have to try and be a hero, but also made sure that he stayed in his simple toddler like mindset, gurgling and clapping happily whenever when filled his diapers since she knew if he had come to his sense, the utter humiliation of his world wide frame would of crushed him.
In a bit of fitting irony however, When Charmcaster when to go and repeat her nasty little trick on Gwen, she turned the tables on the witch and now Ben had a drooling playmate in matching diapers to hang out with during the day under the watchful eye of Ben's mom.

The end