With the benefit of hindsight, Ben would later reflect that everything that was about to happen to him could of all been avoided if the 10 year old brat had just cut back on the sugar, learned to watch where he was going and had just gotten a decent amount of sleep. 
However like the saying goes, Hindsight was 20/20 and Ben hadn't been able to get more then maybe 2 hours sleep since the Tennyson's were parked outside of where a fair would be opening up in the morning AND him and Gwen had gotten special bracelets that would let them get all the snacks and play all the games and go on all the rides without having to keep getting tickets or pay. The bracelets hadn't been cheap either, but Max reasoned it was cheaper in the long run plus he'd done it as a bribe to keep the kids at the fair all day while he took a long needed nap in the rust bucket/had me time.
Because of his lack of sleep Gwen had gotten up before Ben to do a little nature exploring before the fair opened since it was by a park (Ben wouldn't of been interested anyways) and was coming back with a thermos fill of all natural water from a spring she had found and told Ben to stay out of it.
"Oh gee, gosh golly, I can't have any of your boring water and will just have to have juice and soda? whatever will I do?" Ben snarked, rolling his eyes as he finished his bowl of frosted covered chocolate bombs. 
"Oh good, your cranky toddler mode and we're gonna be putting sugar in you. Do me a favor and explore on your own today." Gwen sighed, putting the thermos away under her bunk and going and washing up.
"What makes you think I'd wanna hang out with a nerd li-" Ben was saying when Max cut him off.
"none of that, I want you two to stick together!" he said. "Unless you want me to take the bracelets back and you can just use your own allowances." 
Groans coming from both sides and putting the matter to rest, he got ready for a day to himself as Ben got changed out of his jammies and into his trademark outfit, and then the kids were off to the fair.

For the first half hour the pair actually had fun, riding a roller coaster and playing bumper cars but while Gwen was semi sensible and got just a few caramel apples, Ben was pigging out on cotton candy, the apple,s and ice cream fudge cars, getting fudge and bits of cotton candy stuck to his face. 
"Ben, slow down, you know how that stuff gets you too hyper and then shoots right though you." Gwen said, rolling her eyes as he stopped at anther vendor, getting a triple scoop chocolate ice cream cone, and grabbing a napkin and pulling him over. "At least let me wipe your face!" 
wiping at his face, Ben yelped and tried to pull away as nearby kids snickered looking at the pair.
"Hey! Buzz off! your not my mom! Last warning, buzz off!" Ben growled, trying to pull away but in his base form, pound for pound, Gwen was stronger then him and he couldn't get away. 
At least, not without a distraction. 
"If you would just wipe your own face this wouldn't be a is-" Gwen was saying, focusing on Ben's grubby face and thus missing his arm in action till it was too late. 
and by too late that meant the brat had brought his ice cream cone in a over head arc and squished it on the top of her head, the cold making her let go of him as he pulled away.
"Ha! you were warned!" Ben laughed and snickered, then went from laughing to scared as Gwen gave him a glare that would of terrified ghost freak. "Uh..is it too late to say sorry?" He asked.
"Their gonna be finding pieces of you for a month!" Gwen growled wiping the cone and the ice cream off her head. 
"and thats my cue to run." 
Summoning every ounce of speed he had and having to dart around the other people at the fair, Ben didn't have time to even think about using the watch as with a roar Gwen chased after him. At some point during the chase she had found the time to scoop up a armful of tennis balls from a knock the bottles stand, Tossing them hard and making Ben change direction and twist and turn. It wouldn't be till he was forced out of the crowded fair area that Ben would realize that Gwen had diverted him away from the public with the throws, likely to use some sort of terrible spell or just to have no wittiness as she killed him.
'Jokes on her! with no one around I can go hero!' Ben thought, looking down at his wrist as he ran and starting to select Xcler8, risking a last glance behind him and seeing Gwen's eyes lighting up to show she was getting a spell ready.
The distraction caused him not to see that the root sticking out of the ground or the fact they were coming up to a gentle slope, two factors that had Ben tripped and rolling down the hill smacking the watch and somehow temporarily  disabling it even as he tumbled into a nearby spring.
As Ben splashed in the water and pulled himself out Gwen skidded gentle down the slope and stopped at the bank, smirking as she looked down at Ben.. which was weird she he was now standing back up.
"Ok Ok! Uncle! don't..hurt..me.." Ben cried out, going to raise his arms up to defend himself when he noticed a few interesting facts. 
One: His voice had gone higher pitch (not that he had the deepest voice to begin with) and had taken on a toddlerish tone to it. 
Two: His t-shirt which normally stopped just above his elbows was now down to his wrists, and as he raised his arms..
Three: his limbs had gotten tiny!
Now Ben wasn't the smartest kid around, but even he could one and one together and get two.
"GWEN YOU BUTT! YOU USED A AR SPELL ON ME!?!" He cried out with all the fury his tiny body could muster and shook a fist even as she snickered and smirked. 

It hadn't taken long for Gwen to decide just what to do with Ben for acting like a whinny little toddler, and the fact that she had in fact found a surviving off spring of the fountain of youth that they had run into earlier in the summer made the punishment she had in mind even easier.
The spell she had been about to cast had in fact been one to put a field around his watch before he could use it but that had become a moot point, or so she assumed as the now 4 at the oldish, though Gwen would put it more likely at three, Ben growled and slapped at the watch over and over, huffing and trying to jump up and down till his way oversized pants tripped him up and he did a spinning fall and ended up on his butt.
the dork's bottom lip trembled and then he was bawling and flopping around wailing about how this wasn't fair and for Gwen to undo the spell.
"Shhh It's ok Ben..there there..I'm here." she coo'ed kneeling down and hugging him, rubbing his back and using a spell to shrink his clothes to fit his new tiny form, though leaving room in the pants as she ballooned his undies out into a bulky diaper that was noticeable under the pants.
She of course toyed with telling Ben the truth about how he had been de-aged but then decided letting him think she controlled how long he was all small would be more fun.
'Plus with me having all that water I took to study..it's not like I don't control it in a way anyways.' Gwen mused as Ben started to calm down, then noticed the bulky diaper around his hips.
"Gweeeeennn! I don't need diapies!" Ben whined, starting to tear up again and she conjured up a pacifier, popping it in his mouth and smirking as his nursing instinct took over and he suckled on it.
"Hush little guy, we both know how many accidents you had last time you were this small, and this way we won't have to keep going back to the rust bucket every time you wet yourself." Gwen said reasonably, leaving out the part she could of just cleaned up any accidents he had in his pants. 
Ben huffed and whined behind his paci, but it wasn't exactly like he had any room to argue, at least for the moment. 
"Come on, I'll Carry you back up the slope and then we'll get back to the fair, I'll find you a nice Merry go round to ride." She promised and got a muffled whine from him as she picked him up in her arms and headed back.

As soon as he could Ben wiggled out of Gwen's arms, landing on his butt with a soft thud though he wasn't hurt due to the thickness of the stupid diaper she had put him in. 
'Stupid Gwen thinking she's sooo smart! I should just unleash a massive poopie in the diaper and make her wipe my butt!' Ben fumed and batted away her hand as she went to help him get up. 
then he pictured her laughing and pointing, teasing him about willingly using the diapers and dropped that idea.
'new plan, keep the diapers nice and clean and get some undies!' Ben thought as he struggled to get up to his feet. 
he ended up having to get on all fours, then pushing himself up onto his feet as Gwen snickered and watched. 
"Oh man, I totally should of recorded that. bet you would get like a million likes on YouTube." She giggled. 
"Your not funny." Ben huffed and then waddled along side of her towards the fair, having to race to keep up with her casual stroll due to his tiny legs and massive diaper butt. "It's not a race!" he whined.
"Yes it is, and your losing." Gwen teased but slowed down, offering him her hand. "Come on, I wanna make sure you stay close to me. the fair can be scary for little guys like you." 
"I'm NOT holding your stupid hand! you likely got like, cooties or something." Ben said and blew a raspberry at her, not realizing just HOW immature he sounded. 
"Righttt..if I did you would have them already from me holding you doofus." She pointed out rolling her eyes. "But ok, I won't make you hold my hand, but you better stay close to me or else." 
"Or else what? What could you POSSIBLY do that's worse then this!?!" Ben huffed, crossing his arms. 
"Oh don't tempt me..but actually I was going to say I'll put you on a toddler leash if I have to." Gwen said, about to comment how Ben  could of been rocking a frilly pink dress or just be in diapers but she wasn't completely heartless. 
"..Whatever." Ben huffed and they walked back into the fair, with Ben staying close to Gwen. 

Thankfully the disturbance that the two had caused had largely been forgotten about and no one asked any questions about how Ben had suddenly gotten so small. the big downside though for Gwen was that Ben being all tiny, she wasn't able to go on any of the big kid rides anymore since she couldn't just ditch him, and he was WAY too short to get on any of them. 
That being said, she had her own ways of making fun and just as she had promised, she brought him over to the merry go round. 
"You have GOT to be kidding me! that's for BABIES!" Ben whined and shook his head. 
"Have you looked in a mirror lately?" Gwen asked, getting anther raspberry. 
"I'm NOT going to ride it and you can't make me!" Ben huffed and crossed his arms, plopping down on his butt and getting chuckles from surrounding kids and adults. 
Never as it turned out lasted all of ten seconds as Gwen just reached down and picked him up under his arms, flashing her Bracelet to the guy working the ride and looking around the various animal choices got Ben seated on a large yellow duck, making sure to use the seat belts that the ride had (the owner didn't wanna get sued if some toddler fell off and brained himself) to get Ben snug and secure. 
"I hope you know I hate you SO much right now." Ben growled as he glared at her.
"Aww, love you too little guy." Gwen said loudly for the sake of the crowd, giving his hair and ruffle and stepping back as the ride was getting ready to start. 
watching Ben bob up and down and going from scowling and huffing to give out giggles and breaking into a smile, Gwen pulled out her cellphone and started to record as Ben really got into the ride..at least until he spotted Gwen recording him and started to have a total fit, messing with his seat belt and making the ride suddenly stop as he got it off and went to climb down. 
as the other children whined and parents started to complain, Gwen rushed to grab Ben and get him out of there, apologizing to everyone for the bratty toddler.

Walking away from the Merry go round Gwen glared at Ben who had a huge smirk on his face now. 
"Really Ben? you couldn't just shut up and behave for 5 minutes!?!" She snapped at him.
"Nope~ better just turn me back now before I go SUPER bratty. I've got a WHOLE bag of tricks up my sleeve." Ben said.
It was a bluff and Gwen knew it, but her tolerance for this little brat making threats had been reached and she decided it was time to take this punishment up to the next level. 
Noticing a nearby dunk tank and the LONG line of kid's waiting to have a turn, Gwen started to work a little discrete magic. the first part was to enchant the target and the balls so that they would be naturally drawn to each other, anyone who went to use the first 15 or so tennis balls could of tossed them away from the target and it would of found a way to hit it. the second spell was a bit trickier but she had been planning something like this for awhile, just having the chance to make Ben do it while a little guy made it better, so she was able to link it so every time the target was hit, Ben would have to take a dump. 
She'd only enchanted THAT many of them since she didn't wanna spend the whole day changing Ben but ironically, unaware to even her the effect WASN'T going to wear off and the balls would be recycled for use over and over. 
"So, you gonna given in or do I have to start playing dirty?" Ben asked, right as the first of the enchanted balls hit the target. 
Instantly the brat face went from a smug look to a open mouthed look of horror as he popped a squat and started to fill the seat of his diaper with SUPER loud farts, getting attention from everyone nearby. 
"Ah geez, they should really make potty training mandatory for attendance.." groaned a goth teen, holding his nose even though the smell hadn't hit him yet. 
"Damn and I thought I could let out a good one!" Chuckled a trucker.
"MOMMY!!" Cried out a five year old boy who was close, running to his mother who HAD gotten a whiff, though the noise had more scared him.
"Geez Ben, you weren't kidding when you said you could play dirty." gwen smirked.
"S-Shut up!" Ben growled between grunt, his pant's puffing out as the diaper likewise did so and the pants were making sounds of distress already fighting hard before to contain his bulky diaper. 
the end result was that the pant's sagged down enough to show the top of his padding if Ben lifted his arms up and it was pretty clear to anyone and everyone that one more mess would mean the end of his pants, and would have his diaper butt even more on display then it already was. 
"Quite the show. finished or do you have a encore in mind?" Gwen asked, wrinkling her nose and then holding it waving a hand. 
"I..Just shut up and change m-" Ben fumed, but was cut off as a second ball hit it's target and with a series of loud poots, the show started all over again. 
"heh, Maybe I should see if we can rent space and put on our own side show. Gwen and the amazing pamper pooper." 

Ben was too busy grunting and pushing to retort, unable to believe that after having just filled his diapers with a load of mush he had more in him but sadly it was happening whether he wanted to believe it or not. 
Softball sized lumps were filling up the diaper even as her cried out and with a LOUD ripping noise his pants blew apart at the hip/crotch level, not even leaving the waist brand of the pants and the leg parts of the pants slid to his ankles and over his shoes.
free to expand without restricting, the diaper rapidly expanded, crackling and crinkle as the cream white diaper covered in little yellow duckies (though the duckies were fading from the back and the front as Ben's bladder decided it didn't wanna be left out of the fun) sagged down and the large lumps could be made out as he finally finished up, a almost visible stink aura coming from him. 
"And THAT'S why I told you not to pig out on junk food." Gwen said. 
"I..I.." Ben whimpered, looking at Gwen and then starting to tear up even as his nose burned from his own fumes. 
not able to put together it was her who had made him mess, Ben looked over his shoulder at the massive load in his diaper and could only agree with Gwen that maybe he had pigged out too much, and in a semi daze reached behind him and put a hand on the seat of the lumpy filled diaper and pressed, as if to confirm yes: he HAD just double loaded a diaper like a big baby. 
The squish confirmed it and he turned back to Gwen and started to bawl, holding his arms out for her to come and pick him up, most of what he cried was in just baby babble but the phase 'change me!' could be made out. 
Gwen came over and picked him up, wincing and turning her head away from the overpowering stink and holding him at arm's leght away at first, but as the bawling got worse she let out a side and pulled the smelly dork in for a big hug and let him sob into her shoulder.
"there there..let it alll out." She coo'ed, even as the dunk tank started back up again after the distraction and anther ball would hit the target. 
As Ben started to unload into the seat of his diapers AGAIN Gwen would roll her eyes.  "not what I meant but I guess go ahead ya little poop machine." 

Due to the looks they were getting Gwen decided to get them out of the public eye, at least for a bit before they got booted out. spotting a rest room and figuring things were suppose to smell in there she got them inside one of the stalls and then sat on the potty with Ben sitting on her lap with a squish, slowly calming down. 
"P-Please turn me back..or at least change me.." Ben sniffled and mewed as Gwen used some TP to wipe his eyes and checks dry. 
"I'll change you after I'm sure you're done going for awhile..no point in going though all the 'joys' of wiping your poopie butt clean if your gonna just crap yourself 30 seconds later." Gwen said. 
"C-Can't you just..do a magic whammy and poof clean diaper?" Ben asked voice hopeful. 
"Thus me, i wish. I can only make the diapers appear, I can't make you get cleaned up. I could get rid of the stinky one but your butt still needs wiping. 
"S-See? If you don't wanna wipe my butt then you should change me back to normal and I'll wipe my own butt!" Ben said, giving a big smile and then crying out a apparently anther ball found it's target,and Gwen's lap got a whole lot warmer. 
"oh god how am I pooping this much!?!" the tot sized hero wailed. 
"Well I always said you were full of shit." Gwen chuckled even as she grimaced at the smell, a factor she hadn't taken into account when plotting this all out.
"NOT FUNNY! I DUN EVEN THINK I CAN WALK ANYMORE!" Ben yelled as the diaper ballooned out like they were in a loony toons short.
"And I can't keep carrying you when your gonna go like this." Gwen said, biting her bottom lip but then her face lighting up. "Oh, Duh. simple solution!"
"Do I even wanna know?" Ben groaned as he finished up, the diaper would be down below his knee caps when she'd go to stand him up. 
"You'll see.~" 

Just as Ben had figured, he really hadn't wanted to know and wasn't happy with Gwen's solution but with him in his poop filled diaper and her controlling not only when he turned back to normal, but his diaper changes he was in NO position to argue..but that didn't mean he had to be happy about it.
Gwen's 'brilliant' plan was to go and rent one of the stroller's that the fair had for him to rid around in though it had ended up resulting in a diaper change before they would rent to Gwen.
"yeah no, I let you put him in that and the stink is never coming out, I'll have to toss it." the lady renting them had said, holding her nose.
Ben had been overjoyed to get into a clean diaper even if it meant being strapped into the stroller (his arguments that he could walk on his own now were ignored as he was strapped in) though his joy didn't last long as they were only 20 steps away from the rental booth when anther ball had hit it's target and Ben was destroying anther diaper. 
"Holy cow Ben, what are you, all bowels?!?" Gwen asked, though the smirk on her face made him start to think that maybe.. just MAYBE Gwen might of had a hand in his messing nonstop. 
'Still, it's just for a little while longer..there's no way she'll wanna keep this spell up plus once gramps see's me, he'll make her undo it.' Ben thought to himself, blissfully unaware that Gwen had no plans for undoing this anytime soon. 
Settling into his role as a stroller bound pamper packing toddler, Ben pointed to a bottle knock down game and to a large stuffed duckie that was being offered as a prize. 
"Gweeeeen, can you win me that duckie?" Ben asked, holding his hands together. 
"heh, of course little guy. anything for my LITTLE cousin." Gwen said, wheeling them over, making plans to get Ben some duck themed outfits. 
Oh yeah, Ben's toddler time summer was just starting, and Gwen was going to make sure it wasn't ending any time soon having plans to go back and get lots more of the spring water. 

NOT the end