Ben gulped and looked nervous as he watched his mom and dad get ready to head out for the evening, on one of their rare date nights that had become even MORE rare after the disaster that had been Julie babysitting him. 
Still his father had insisted that they have a chance to get free from the smelly little wuss who whined and pooped himself at the drop of a hat (and was getting so bad even the noise of him filling his diapers could scare him into pooping even more creating a vicious circle) but as he had pointed out, Ben had always liked it when Gwen looked after him and ergo if they brought Gwen over who even Ben's mom as over protective as she was trusted, the little stinker should be ok. 

Of course what neither of his parents knew was that Gwen had been excited to hear about Ben getting a new babysitter. Sure it had been fun for awhile to have a big chubby baby to play with and to show off, and of course she got a little power trip having him adoring her and obeying her every command (was as much as he was able to) but frankly none of that was worth the many, many dirty diapers. 
So naturally after hearing about how Ben had screwed the pooch so to speak on getting a new babysitter Gwen had made sure to get some alone time with him, saying she wanted to play with the bay, and once they were alone had laid it out for him plain and simple.
"look here doofus, I'm getting sick of smelling like a diaper pail every time I come back from looking after you. so your gonna be a good boy and either convince your parents to get anther babysitter, convince them to take you with them on date night Or I swear your gonna be one sorry little diaper filling wuss if I have to come over and wipe your butt." Gwen said said in a low tone while having her phone playing her baby talking and coo'ing to ben up loud by the baby monitor so neither set of parents would know she was threating him.
Ben, Naturally responded the only way a wuss like him could, going to bawl even as the back of his diapers started to bloat out but Gwen just popped a large pacifier in his mouth and went to get her phone back, not even needing to speak to make it clear that if he was a smart little wimp, he'd keep the paci in.

Now here Ben was, a mere 3 weeks later after Gwen had made her threat and Ben was already filling his diapers, sucking on a large black and green paci and in a white t-shirt with a black stripe down the middle of it (Onesies and sleepers were pintless with how big the wusses boom boom's were, there were dents in the walls from where buttons and zippers had gone flying off from a mega dump) and praying that Mommy and daddy would realize that something was wrong and decide to call it off and stay home.
Sadly for Ben, since he was SUCH a epic crybaby wimp who filled his diapers and whined whenever mommy was leaving anyways, they couldn't tell anything was wrong besides the normal 'please stay mommy!' routine.
His diaper had swelled out big enough under his chubby butt that he was almost half crouching on his chubby legs, the formally white padding was discolored a ugly blotchy brown and there where baseball sized and larger lumps in the back, the front hadn't been shared either as any sort of wetness indicator had long since been banished from his diapie.
"Now Benny, I want you to be a good boy for your cousin, I know you two normally get along great anyways but well, you've been a bit cranky today." His mother coo'ed, Bending down and tickling Ben's chin and getting his to giggle and smile behind his paci despite his terror, and as always she seemed immune to the stink coming off of him.
His father meanwhile was quietly muttering about how she was gonna smell like a diaper pail now, and they were gonna have to drive with the windows down and hope for the best.
Ben started to take his paci out, to try and tell him mommy what was gonna happen if they left him alone with Gwen, but just as he got it out, a line of drool going from it to his bottom lip there was a knock at the door and before he could say anything thing his dad called out "come in!"
The Door opened and there was Gwen, a big pleasant smile on her face and a backpack over one shoulder which right away started up a fresh series of bubbling fart's and ben's diaper started to expand more.
Gwen had never brought over her backpack before when she babysat and Ben just knew that it had to be filled with all sorts of horrible stuff and went to cry out and warn his mom, though the effort of filling his diaper and his fear had him say something else entirely.
"Going Poopie!" He babbled babyishly and got a warm chuckle and a pat on the head from his mother. 
"Yes you are!" She giggled. "Thanks for coming over Gwen, Your the only person really who I can trust with my sweet little Benny." 
"oh, it's my pleasure Aunt Sandra! You know I just LOVE playing with Ben." Gwen said, a warm smile on her face but as she locked eyes with Ben the little wuss knew she was letting him know how SOL he was.
"What's with the backpack?" Ben's dad asked, trying to be polite but also nodding towards the door, trying to hurry his wife out the door before Ben's stink clung to her any worse and she'd have to shower and change. 
"Oh I just have some homework I need to finish Uncle Carl. it's the advance classes I'm taking, they really pile it on. Don't worry, I'll wait till little benny is fast asleep before I start." Gwen said. 
"Of course, you do what you gotta. it'll be nice having someone for your generation of the family able to count hi-" Ben's dad started to say, but a look from his wife hushed him up. 
"Do you want me to change Ben for you before we go?" Ben's mom asked.
Ben looked hopeful, even as he made anther lump in his already packed pampers. If his Mom changed him he might have a chance to warn her about what Gwen was likely pl-
"Nah that's ok. It won't be the first time I've changed one of his mega bombs and likely won't be the last." Gwen said, locking eyes and giving him a warm smile but her eyes said loads to him. 
'thought you had a way out eh smelly pants? no way. you're in for it all night long!'
Naturally, this made the little wimp do what he did best: Crap himself.

Gwen watched out the window, thankful that the little spell book she had gotten her hands onto had a spell in there for removing a persons sense of smell for a few hours otherwise with the lack of diaper changes she planned on doing tonight she'd of been suffering just as bad as the little wuss was gonna. 
Once she was sure that her aunt and uncle were gone and not coming back Gwen turned around and looked at Ben in his shit swelled diaper, even for the brand that Aunt Sandra got it looked like it was reaching it's bursting point.
"So, looks like somebody couldn't convince mommy and daddy to stay home or try and find someone else huh?" Gwen said, tugging her backpack off and unzipping it, reaching in and bringing out her spell book. 
"G-Gwen Please! I tried, I really really did!" Ben mewed, trying to scoot back but well, his diaper was now almost half the size of him and he was basically stuck in place. 
"Benny Benny Benny.." Gwen tsk'ed, wagging a finger at him and then glancing down at her book. "Didn't you ever hear? there is no try. there is do or do not."
Muttering a few strange words a bolt of pinkish energy shot out of Gwen's hand, hitting Ben's diaper as the wuss screamed and started to go again, even though he knew that his diapers couldn't handle anymore, he'd end up leaking and get in trouble for that an-
And ben looked around, shocked as even as he pushed out a fresh (well, not so fresh but still) load into the diaper it just glowed and started to expand. 
"W-What did you...?" Ben asked, even as he balled up his fists and groaned, his tanks were running on fumes as he made one or two more smelly lumps to the frankly toxic diaper. 
"Aww, baby need more fuel?" Gwen asked in a mocking tone and she turned the pages of the book a few time and then some more funny words and..
And just when ben had thought he'd pooped all that he possibly could his tummy bloated out and it was like he'd been to a all you can eat place! 
Instantly he was making huge poopies, making his diaper glow and crackle which naturally only made him MORE scared which made him.. well you get the gest of it. 
"W-What Ohhh guuuuhhhhh did you Ahhhh do to me!?" Ben cried out, making scrunchie faces and curling his toes as the diaper grew and grew and his feet couldn't even touch the floor anymore. "It's evil magic isn't!?"
"Why Benny, I'm HURT! Hurt and upset that you could accuse me of something like that!" Gwen gasped, a hand to her chest faking a hurt look, then smirking. "But Yeah, it's evil magic. That diaper is stuck on your butt till it weighs twice your weight, and with how many pounds you've been packing on it'll take awhile. But in the spirt of being a kind and wonderful baby sitter I filled you up to give you a fighting chance of not going to bed in a shit swelled diapers." Gwen paused and tapped a finger on her jaw, looking thoughtful. "though come to think of it that's basically how you go to bed every night anyways so I'll have to make it more interesting."
Just the thought of Gwen having to make things 'more interesting' was enough that Ben's guts doubled down and his diapers were filling with mush even faster, just sitting on the bloated, brown and lumped filled diaper had him a little bit taller then Gwen was!
"Oh -I- know, if you can manage to fill the diaper up enough to meet my terms, then you'll get a diapie change before bed. Fail.. and I'll put you in a stink suit and you'll be stuck huffing your fumes all night long, with a little magic thrown in to make you more toxic then normal. Of course normally doing something like that would fry some brain cells but.." And Gwen laughed. "Widdle itty bitty baby benny doesn't have two brain cells to rub together anyway does he?" She mocked.
"S-Stop being a meanie!" Ben whined, his butt starting to hurt from all the filth around it and the effort of going almost non stop. 
"Tell you what Benny, I'll stop being a meanie.." Gwen started, putting her book away in her backpack, turning away from ben and then turning around, a realistic werewolf mask on her face with a voice modifier attached and making her sound even worse.
"IF YOU CAN MAKE ME!" She growled.
Ben let out a scream and well, his diaper swelled even faster as he slumped forward, having passed out in fright. 
Gwen chuckled and caught him, then blinked in shock behind her mask as the spell on the diaper blinked once, twice.. three time and then faded. 
"..Holy shit.. he actually managed to.. Jesus Benny, you're not much of a big kid but when it comes to pamper packing your a superhero." Gwen started, trying to figure out just how the hell she was gonna change the epically loaded diaper. "..I really didn't think this one though.."

One magic assisted change later (though Ben semi whined she cheated) and the big baby was sat in front of the tv, twitching and looking over his shoulder every 20 seconds at Gwen who APPEARED to be just reading a book while one of his mindless shows was playing but Ben had no doubt she was waiting to scare him again. 
Even if he'd had decent bladder control (Which well, naturally he'd never had and never would) the wuss had soaked his diaper four times already and was sucking on a bottle of apple juice since he was familiar with the taste, and could tell to a degree if Gwen was messing with him.
Gwen for her part didn't bother with such mundane things as ex-lax or pee pills with a total and utter wimp like Ben, his own body was basically primed to go off at the slightest thing after all.
As such she could only smirk as her magic came into play and waiting for JUST the right moment, she had a little jump scare planned for the wimp that would have his hyper bowels doing what they did best: AKA pooping himself stupid.
Ben turned to look at her again, his bottom lip trembling and she lowered her book, a fantasy novel since naturally she didn't actually have homework and scowled at him, a act that it itself had a rumbling poot come out of him. 
"Jesus Ben, just watch your 'tard cartoons and stop looking at me! when I'm trying you'll know it!" She growled at him, which she was sure that in itself had fart stains in his diapers.
Ben whined and whimpered and turned his attention back as ruby was about to scold max again when suddenly the cute harmless bunnies on the screen turned to face him, then got red eyes and face and seemed to jump out at him.
the effect was to the surprise of no one, Ben screamed bloody murder and the back of his diapers started to fill up rapidly, smaller lumps coming out those he was pooting and stinking up the place as his diaper expanded, going triple it's normal size in mere seconds and apparently his normally never ending tanks hitting their limit as while he farted and whimpered, the diaper didn't grow any bigger, setting on a large but more manageable mess as Gwen put her book done and scooted in next to him.
"Jeez Ben, knew you were a WIMP and a WUSS,.. but is max and ruby REALLY too scary for you?" she asked, as if she hadn't make it all happen.
"Buh..buh..buh.." Ben stammered, his bladder going dry as he shook and trembled. 
"Well said.. come on, better get you changed AGAIN, then get some num nums in you." Gwen said, rolling her eyes like she had ALL the problems in the world when inside, she was cackling with delight.

One gross diaper change later and Ben was in fresh huggies and wearing a bib that declared him number one at going number two, his arms pinned down by the tray as Gwen cooked up a meal that would A) make ben go like a champ, she wanted a stinky diaper like before even though she doubted she could get it, and B) would be gross and make the big baby make all sorts of faces.
"So Benny, I made a super awesome din din for you." She giggled, bring the pot of foul smelling mush over and scooping it out into a bowl in front of him. 
Even for Ben, who's dirty diapers SHOULD of burned out his sense of smell ages before wrinkled his nose and made a face, turned around from the dark green goo for lack of a better term. 
"M-Mommy already gave me din dins!" Ben weakly tried to argue.
"Well that might be true, but a stupid wussy diaper pooping expert like you needs all the fuel you can get. after all, I'm not done with you AND you should know exactly what you'll be eating every. single. time. I have to come over and watch your smelly butt." Gwen said, going from a sing song voice to a hard one and glaring and making Ben fart lots =but his tank was truly on E so he just trembled. 
"I made a nice hardy stew for you, or is that ew?" Gwen said, putting the pot down and getting a spoon in the gross mixture, scooping up a spoonful and bringing it up to his mouth.  "I won't tell you what's in it, but trust me when I say this will have you back to making those baseball lumps your semi famous for." 
with that she pressed the spoon on his mouth, but Ben was holding it close, trying to turn away and getting the muck all over his face.
"Ben, I know I've been mean and awful to you tonight. and I know it ha to be hard seeing the cousin you thought loved a wuss like you being so mean." Gwen said, her voice soft. "but trust me when I say one way or anther this is going in you and I know where a enema kit is, so you might as well just open up." she added with a cackle.
Ben, never know for being a bright bulb due to being a diaper pooping wussy momma's boy who'd never even gone to pre school,,, suddenly saw the light and in a flash of rare brilliance opened his mouth, though as the muck touched his tounge and made his eyes well up from tears even as he made a face, started to wonder if just taking the enema would of been better.

One LONG feeding latter followed by a bottle of baby formula that tasted more like chalk and had been burping like crazy even after Gwen burped him, and the gassy big baby was sat back on the living room floor, no cartoons on but given toys to play with and Gwen offering up a challenge.
"if you can come up with a story with your toys that's entertaining enough, Not only will I stop tormenting you but I'll go back to the doting babysitter I was before." She promised but then leaned in, making ben fart and a little bit more. 
"Bore me however.. and I'll scare you SO bad you'll need a diaper change every time you see me.. so.." and she snickered and kissed her index finger and middle finger of her right hand then tapped them on his forehead then sat back in a chair. 
"Make it good."
Ben gulped big time but even with his weak wimpy mind he knew that this was his best chance and even as his tummy gurgled and cramped, he scrambled to get his toys set up and tried to come up with a story, Nay, a epic legend to tell Gwen as she leaned back on the couch and tapped a foot, raising a eyebrow and tapping a finger on her wrist. 
"Tick tock wuss." Get started soon or forfeit your shot." She said. 
"Ok! Ok ok ok!" Ben gulped, his fat diapered butt quivering in fear and taking a big breath he started. 
it was a legend about how the stuffie kingdom were stick and tried of the nonsense toys from the dreaded toy chest across the room were getting used more by the great and powerful baby god. the stuffies figured as they were more soft and huggable they should be the only ones to be played with while the nonsense toys led by King rattle and prince jangling keys thought that they could share the attention.
Before Ben could co on about the epic war that was sure to happen Gwen both blew a raspberry and gave him a thumbs down AND had taken out her cell phone and cued up the fail music from the price is right. 
"Sorry smelly, that story stunk almost as bad as your diapers.. So it looks like you get to keep being a scared shitless little twerp." Gwen said with a nasty smirk on her face. 
Hearing that he had failed his only chance to get nice Gwen back and having his creative genus insulted (His mom LOVED his stories!) Ben's bottom lip quivered and he started to bawl even as with a sputtering series of farts he started to do the one thing he was good at: Making poopie diapers.
"Ugh, i swear to god, you must be all bowels!!" Gwen complained, holding her nose and waving a hand. 
Naturally, such a mean insult only made the pamper filling even worse.

Gwen tapped her chin, she really had to come up with a way to torment Ben or at least get him to stop hyper messing his diapers so bad and then as a terrible horrible idea came to her, a smile that would make the Grinch proud came onto her face and she pulled out her spell book and locked her eyes on Ben. 
"W-what are you gonna do?" He asked in a trembling voice, going pale. 
"Relax, this isn't gonna hurt.. I'm simply using a bit of temporal magic to make i-" Gwen started as she made the gestures in the air, pink magic showing up but was cut off by Ben. 
"What's 'temporal' mean?" He asked. 
"..Time magic. Time as in that thing you still can't tell because your too busy pooping what little bit of brains you have out."  She said, rolling her eyes.
"HEY! I can tell time! After super kitten buddies is on it's normally lunch time!" Ben huffed, still making softball sized lumps in his diapers as he crossed his arms.
"Wow. Gee, that TOTALLY put me in MY place." Gwen said, rolling her eyes and then added. "If I may go on?"
"Hehehe Yeah, I'll allow it." Ben giggled, having totally missed she was being sarcastic. 
"ANYWAYS.. This will make it once your diaper hits a certain weight, even if your still crapping yourself little the little poop machine you are, the rest of the waste." She paused as Ben looked confused and went to ask something. "It's anther way of saying poop. anyways, the rest of it will be time displaced and end up popping into the back of one of your diapers later on when there's room. Basically.. your never gonna get to enjoy a clean diaper again." Gwen said with a smirk. "Might motivate you to potty train~" 
Ben Naturally went wide eyes and started to yell that that wasn't fair, that she couldn't do this but by that point the spell was done and Ben whined and whimpered, the thought of being forever poopie wasn't a great one. 
Though then again he was semi what forever crapping himself, so it couldn't be THAT different but logic had no place in Ben's widdle mind. 

Date night had gone somewhat well, or at least as well as it could since Sandra had kept wanting to call and double check on Ben all night long. Carl had of course talked her out of it, pointing out how much Gwen and Ben got along and that it would be alright, Gwen wasn't anything like Julie. 
Carl himself of course never bought that Julie had been some horrible horrible pervert and was more prone to listening to the girls side of the story and her horror had almost being smothered under ben's butt, though he knew better then to DARE suggest that Ben had been at fault to his wife. 
Coming in there the door there was the usual blast of stink that always greeted him when he came home, and he found himself still amazed that A) his sense of smell hadn't burned out by now and B) that his wife could not only endure such a smell but break out into a big grin upon getting a whiff of it. 
"MOMMY!" Ben cried out, crawling over with a droopy diaper butt though Carl was shocked to see it wasn't as bad as he'd of though.
Normally by now ben would of had a personal bean bag chair going on around his hips. 
"Hiii my little stinkbug, did you have fun with Gwen?" Sandra said, kneeling down and scooping up the chubby little pamper packer and rocking him in her arms, then holding him to her chest with his head over her shoulder. 
"Uh.. yeah! Me and Gwen had LOTS of fun mommy! But.. Not as much fun as you and me have!" Ben said and if Carl didn't know better he would of sworn there was a brief look of fear on ben's face, but then the baby was going on. "But uh.. I don't think I needa babysitter anymore, you can just stay home.. or.. I'll look after myself! Cuz Gwen was telling me what a.." And Ben trailed off.
"I was telling benny what a super awesome little guy he is and how smart he is." Gwen said, coming over and ruffling Ben's hair. "Sorry for him still being in a stinky diaper, he insisted on showing you how much control he has." Gwen chuckled. 
'Heh, She's a good sport about this.' Carl thought and pulled out his wallet, getting a 20 out for Gwen and slipping it to her. 
As a rule she wasn't suppose to be paid for looking after little Benny but Carl thought anyone who was willing to put up with his constant dirty diapers so be compensated for it.
"Well, I don't think your ready to stay home alone yet Benny.." Sandra was say and giving Carl a look. 
"..And we can't just stay home ALL the time either." he added, and smiled a Gwen. "Looks like your services will still be needed." he chuckled and led her to the door. 
"Oh I don't mind.. I'm sure me and Benny can have LOTS of fun.. right Benny?" Gwen said and gave Ben a big smile that had the little wuss whimpering and then bawling and farting.
Carl was shocked, normally ben's diapers would of been expanding out more with a sob like that but Maybe Gwen was onto something with him having SOME control and as he walked Gwen over to her house, he heard his wife gushing and coo'ing.
"Awww, your so happy about Gwen babysitting you your crying! Adorable!"

The end