I read a fic about Dean with severe allergies earlier today, and I was inspired, though this kind of allergies is canonical. Takes place beginning of season nine, with human Cas living in the Bunker.

When Dean awoke with a scratchy throat, a running nose, and every inch of his skin itching like there was no tomorrow, he muttered a curse.

He huffed angrily, knowing exactly what had happened and who had caused it. There was only one thing in this universe that would cause this sort of reaction from him.

And it was sitting right next to his face on his pillow.

"Gah!" Dean immediately scampered out of bed, glaring at the little tortoiseshell kitten that was curled up, sleeping peacefully right near where his head had been resting. He sneezed harshly.

It must have awoken at his sudden motions, because the cat's eyes blinked open groggily and it looked at him in what seemed like bemusement.

"What're you lookin' at?" Dean growled through his swollen throat.

The kitten yawned.

Now his eyes were starting to water, and Dean couldn't help but rub them. He coughed weakly and sniffed up the clear snot that was dripping down his face.

Fan-freaking-tastic.

"Get out," Dean demanded. His words sounded a little muffled and unclear, but that was the congestion messing with his voice. Stupid allergies.

The cat blinked at him.

Dean cursed once more and ran out of his room, not minding that he was only in his boxers and a t-shirt, to find the perpetrator of the whole incident. Because there was only one person who would bring a freakin' cat into the Bunker.

And he was currently scouring the kitchen.

Once Dean entered the room, Cas said, "Dean, where do you and Sam keep the coffee?"

Dean scowled. "This isn't funny, Cas." He sniffed, scratching at his arms with a new furiosity. His throat felt nearly swollen shut it was so scratchy, and he probably looked like he was crying.

Cas frowned and tilted his head to the side. "Is everything okay, Dean?" he asked somewhat cautiously.

"Not really, Cas." Dean opened a kitchen cabinet, reaching for the antihistamines that they usually carried around just in case Dean's allergies were triggered during a hunt. He coughed slightly, shouting another expletive once he realized that they were all out of the medicine he was so desperately craving. Turning angrily back towards Cas, Dean yelled as loud as he could manage, "There is a friggin' cat in my bedroom, and now I feel like crap 'cause the dumb thing was sleeping right on top of my face!"

Cas' mouth formed a small "o". "So that's were Mittens has gotten off to?" he questioned.

"Mittens?"

"Yes, that is the kitten's name. I found her outside yesterday while you and Sam were away last night." Cas' eyes turned wide, resembling Sam's signature puppy dog eyes. "She was terribly hungry, Dean. I'm sorry, I did not know you were allergic."

Dean pinched the bridge of his still-running nose in attempt to calm down. Cas hadn't known, it was an accident, and they'd move on, right?

But Cas didn't know how hard it was to decontaminate bed linens of cat allergens. It seemed like Dean's supposed day of recuperation after a hard hunt would be spent doing laundry.

"Whoa, Dean." Sam chose that moment to walk in. He stared at Dean through wary eyes. "You look like crap."

Dean huffed. Did Sam think he didn't know that? "Shuddup."

Sam frowned. "Is there a cat in the Bunker? 'Cause that's the only thing that would make you react like that…"

"What don't ya ask Cas over there?" Dean nodded in frustration towards the former-angel's direction. "I'm gonna go see if we have any meds in the car."

Once the red and swollen mess that was Dean had left the Bunker, Sam started laughing. "Man, Cas, what happened?"

Cas relayed the story as he'd told it to Dean, which only caused Sam to laugh harder. He tilted his head once more. "I do not believe this is humorous, Sam," the man said cautiously. "Dean looked truly miserable."

Sam shrugged. "He'll be fine. Basically when this happens, his throat swells up a bit, his nose drains, and he becomes an itching mess. I'd be surprised if hives don't pop up within the hour."

Cas looked to his feet and muttered, "Will he be mad at me? I was only trying to help the kitten."

"He'll be frustrated as long as his allergies are acting up, but he'll get past it," Sam said, casually patting Cas' back in assurance. "But for now, you'd better get that cat outta here."

"But—"

"She can't live here, Cas," Sam pointed out. "Our lives are too inconsistent. She'd have a better life with another owner."

Cas sighed. "I…I suppose so."

"C'mon, man. I'll drive you and her down to the shelter."

Cas grabbed the kitten and they walked out to the Impala to find Dean in the midst of a body-wracking sneezing fit.

"I am truly sorry, Dean," Cas whispered, holding Mittens close to his chest.

Dean chuckled and rasped, "Screw you, Cas."

Apology accepted, it seemed.

Thank you for reading, please feel free to leave a review. :)