Kagome smirked as she looked at the two so called badass demon's in front of her, who were both whimpering and holding hands as they both sucked on oversized pacifier's while wearing matching tan T-shirts that both read 'Mommies little guy' on the front and also were both in matching white and blue diapers that forced their leg's apart. 
"Alright boys, we all know the deal.. while I've had fun making you BOTH my ickel widdle guys and making you two at LEAST bi.. Just as I agreed to I'm giving ONE of you a chance to man up and became a daddy dom to the other and get to finally make love to me, not just your diapers." She said in a sing song voice, then pointed over to a 8 foot tall and massive ly teddy bear on the floor. "Of course I'm well aware that the way your gonna EARN that chance is with only last huggie humping session but well.. my pussy, my rules." 
The demons both whined and nodded slowly, Inuyasha squirming more then Koga as he looked at the tan teddy bear and gulped nervously.
"Now again, it's first one to spurt gets to man up, but don't worry if you don't, you'll still be in my life as my darling little babykins." Kagome went on, giggling and winking. "And don't, forget, a tie means both of you stay pampered. you'll have a hour to blow your load though since I'm a kind and fair mommy.. Oh! you both finished your ba-ba's right? I don't want any excuses about getting all dehydrated and THAT'S why one of you lost." 
Both babies nodded, though it was Koga who had a wince on his face a he looked over at the one litre bottle he'd ad to drain, it had tasted funky and not like the normal formula Kagome had been giving them both which as much as he might not want to admit it..  he'd kinda grown to love the taste of. 
"well then, I guess it's time to get this started then! off you go little guys! Think sexy thoughts as you make love to your huggies and Mr. bear for hopefully the last time!" Kagome coo'ed, getting a stop watch out and smirking. 
unlike the other two she already knew what the outcome of this little race would be since she had spiked both ba-ba's with a drug that promised it would keep boys from being able to nut for at least 2 hours. 
Sure it was MEANT for humans but she was mostly sure it would work on the full and half demon babies in front of her and as each one of the pampered dorks took their positions, she clicked on the timer as she yelled out "GO!"

Inuyasha started off strong, humping as hard as he could though his smaller size downstairs and the thickness of the padding around his hips meant he knew it was a uphill battle vs. Koga's bigger size. Still, the half dog demon smirked a little behind his paci as he humped as hard as he could, closing his eyes and picturing sexy thoughts as he had a advantage that Koga didn't in this contest: He was a true blue premature ejaculator and while any other day he would of been ashamed of it, it was his ace in the hole. 
Smirking and humping, he tried to picture all of the naughty things he'd do with Kagome, while making Koga watch in a poopie diaper sitting in a playpen but even as he felt himself getting close, he couldn't QUITE get over the edge somehow! And even worse: his mental images of Koga as the sulking stinky cuck kept shifting to Inuyasha in the smelly pampers being cucked. 

Koga growled behind his paci, the teddy's leg and his bigger size meant he was getting the full on experience and even knowing Inuyasha was a little quick shot he was positive that he could fire off a load before the runt. It helped that Kagome hadn't actually let him cum in the past two weeks (well, technically she hadn't meant to let Inuyasha cum either but the little mutt had a bad habit of one wipe too many and SPURT) so he was sure it would even things out.
His strong humps and the padding hugging his big cock had Koga moaning and the paci dropping out of his mouth as drool ran down his chin, Picturing him and Kagome fucking, him bouncing up and down in a poopie diaper on her kn-
Koga froze, blushing and eyes going wide. 
'Why the FUCK would I..Ngggh.. Focus!' He scolded himself, going back to humping double time but even as he tried to picture all the different things he wanted to do to Kagome, it all ended with him in stinky diapers and cummings hard!!
'It's.. it's just because..' Koga tried to tell himself but then gave up. 
this was NOT the time to over think things, this was the time to go mentally blank and hump!

Kagome giggled, sitting back and keeping a eye on the stop watch even as she slurped on a soda, having her cell phone up and record the boys. It was clear the twin big baby demon were having some issues, though she couldn't of known about what was going on in their heads. setting her drink down she tsked slowly as she took in the time.
"Really? 20 minutes down already boys.. I'd of thought ONE of you would of been cummings buckets by now~ could it be my widdle doggies wanna stay pussy free big babies?" she called, getting whines and whimpers in response and both of them seemed to double down on their efforts. 
"Better hurry~" She called over in a sing song voice, knowing that she was gonna be able to make a FORTUNE selling this video to a porn site. 

Anther 25 minutes went by and both demons were getting desperate now, time was running out and even Inuyasha had lost his paci now, whining and whimpering and the sounds of them both breathless and begging to just spurt already, confused why hadn't was making Kagome more then a little damp and had forced her to open up a window as the demon musk in the room was making her a little dizzy. 
"I..I Just.. oh gawd.. Why can't.." Inuyasha mewed, actual tears starting to build up in the corners of the little wimps eyes. 
"F-Fucking shut up! I'd of.. of nutted by now if!!" Koga roared, gripping tight on the bear and slamming down on the leg which was starting to show signs of stress, it was gonna rip and spill it's stuffing out and soon. 
Inuyasha went to say something but then felt not only his bladder but his bowels suddenly fill up and he started to let out little poots with each hump, even as Kagome giggled.
"Inuyasha sweetie, that's the wrong kinda messy you need to make~"
Koga like wise went to snark at the white haired pup when a loud brassy poot came out of his end and then almost in stereo, both big babies started to fill their diapers, in more ways then one. 

For Koga, as the massive load worked it's way out and pressed down on his prostate, he howled and came harder then he every had in his life, the back of his diapers bloating out big time even as he his tounge stuck out and his eyes rolled back in his head, the plush leg of the teddy under him giving out and stuffing going al over but he didn't care, flopping down and coo'ing in delight, positive that he had won in the small tiny corner of his brain that was able to process anything beyond the mind destroying orgasm he'd just had. 
On Inuyasha's side of things his uh-oh's came out as well but his orgasm was more like a weak watery tinkle, and he barley felt any real pleasure from it, the fact that he'd basically pooped himself into a ruined cummie had the tears that had built up in his eyes spill over and he sat up on his leg of Mr. Bear, hands coming up and rubbing at his eyes as he started to bawl. 
"M-My cummie was ruinnned!" he sobbed and hiccupped. 
Kagome, who hadn't expected either of them to cum at all but was glad it had been close enough to make calling a winner impossible, just smirked and came over, giving Inuyasha a hug and a kiss on the cheek. 
"Shhh it's ok sweetie. I'm sure your next stinky diapie cummie will feel better." She promised.

As it turned out, that was a lie. the drugs that Kagome had given the demon had a lasting effect because of their demon natures, with Koga now only being able to cum while loading his diapers, but always having massively powerful one. Even when given the chance to have sex normally, he just couldn't get it up anymore but it didn't seem to bother him. 
If anything Koga's IQ seemed to have dropped from it all, his only baseline desires were to load up on as much food as he could get in him, so he could make big stinkies and cream, then have a nap. .. something that started off fun and cute but after awhile Kagome started to get sick of it.
She was currently working on a way to get the rest of his tribe to take him back but they were of the mind set that she'd ruined him, she could deal with him. 
Inuyasha meanwhile had turned into a whimpering cry baby, who was constantly cling to Kagome and bursting into tears at the drop of a hat and who despite both of their best efforts, couldn't even get hard at ALL anymore and just had limp dick ruined orgasms. 
He at least could semi function SOMEWHAT though Kagome had decided if he was gonna be such a sissy, she'd dress him for the part, so he had a closet full of dresses and skirts and put up ZERO fight in whatever she wanted to dress him in and was a good little gurl and helped with chores. 
The final irony of all of this was Kagome had always had plans to make at least one of them, maybe both, come out of babyhood when she got sick of changing shitty diapers but because of her own little games she was doomed to be stuck wiping poopie bottoms for the rest of her life. 
Poetic justice if you think about it. 

the end