"Phew! Someone made nana a very big present, didn't they!" The matronly cow wiped down the smooth calf-butt wrapped up the stinky used diaper into a ball. She tried to put it in the pail, only to be presented with a stinking mass of used diapers. 

"Oh, this is getting rather full." The matronly cow looked down at an overflowing pail. "Guess I'd better empty this one."

"Um, N-No need!" 

She turned around to see a shy little otter standing by the door. He blushed as the nana turned to look at him. 

"I-I mean... if you'd like...?" He quivered, glancing between the calf and the cow. 

"That's very gracious of you!" The otter sagged with relief as the cow smiled at him. "Let me just finish up with the little one and I'll leave you to it!" 

She set the diaper to one side on the surface as she set about oiling the rump. Afterwards, she taped up the fresh diaper snuggly around the cub's waist. The otter stood, watching, fidgeting with his hands. 

"Alright, nice and clean now! Ready for playtime!" She gave a nod to the otter as she carried the cub back to the playroom, shutting the door behind her. 

The otter sighed, excitement and nervousness building. This was insane, what he was planning, but the idea had been eating at his mind for far too long. The calf's big, messy diaper was calling to him. 

With trembling fingers he undid the straps and opened it, unfolding it to reveal the thick, brown sludge that the cub had filled it with. 

"Wow... just what are they feeding you..." He panted, looking down at it. He gave it a lick, then pressed his muzzle against the rich brown fudge. "Fuck... this is so fucking depraved..."

He snorted and snuffled as he gobbled the messy diaper filling, growing hard from the sheer debauchery of it. His face painted from from the cub-scat scraped against it. There was no way he could go out looking like this, one glance at his face and everyone would know what he'd been doing. 

He was all in now. 

He unscrewed the top of the diaper pail, staring into that huge pile of balled-up, stinking diapers. He took a deep breath of the stink and sighed. 

Time for the plan. 

He took out a large plastic bag, gathered up a random smattering of the diapers, focusing on those who were less-filled or only wetted. Once he'd filled it, he carried it as fast as he could to the dumpster outside, tossing it in, then he ran back to the changing room before anyone could catch him. 

With a manic grin on his face, he stripped down, hiding his clothes behind the changing table. He stroked his stiffening dick. 

He gripped the sides of the pail, took a deep breath, and clambered into it, sinking into the stinking mess. He ground his hips up and down, feeling the warm, sloppy mess spreading around him. 

He tore his paws down, ripping open as many tapes as he could. The stinky, sloppy mess spilled around him, coating his body and sending his dick into dripping overdrive. He was getting close! 

The door was opening! 

Quick as a flash he dropped, pulling the lid of the pail back on after him. He sat in the opened, messy diapers, quivering staying as quiet as he could. 

"Phew, someone's a very stinky boy!" Slightly muffled, he could hear the cooing voice through the thin lid. "How have you been dragging this thing around for so long? You're one step away from a blowout!"

He heard the tapes going. Even in his musky prison, he could smell the hot stink of fresh cub-shit. He let out a soft moan.

"Hmm?" 

The otter clamped his paws over his mouth, keeping as quiet and still as he could. His cock was twitching, right on the edge. 

"Were you trying to say something, little one?" The nurse cooed again to the cub. "There! I think you'll be much happier if you're not lugging about all that weight!"

The otter quivered as the footsteps came closer. There was a flash of light as the lid opened. A moment of terror when he thought he'd been spotted. Then the thickest, sloppiest diaper that he'd even seen, with muck dripping through the leg-holes, pressed through the slot. It could barely fit, staying stuck in the slot for a moment before falling, with a splat, right on his face.

He let out a silent squeal. His cock blew out a hot load into the messy of diapers, impregnating the mess with his desperate seed. 

"Oops, look like we've got a little queue forming!" The nurse chirped happily. "Plenty more diapers to go! Let's get you changed nice and quick."

The otter shivered, arousal growing even in the midst of his orgasmic bliss. There were so many more diapers to take. He was gonna be a good pail and take them all...