Here comes the fluffy one! Hope you like it.
There are two purely human experiences Cas can't get used to. As an angel, he has known exhaustion, pain, weakness, even - in a way - hunger, when he'd spent more energy than his grace could provide. Now that he is human, some things are absolutely new.
Boredom is one of them. As an angel, he maneuvered within time and space, which allowed him to keep himself busy all the time. Now that time is fixed he feels like he is trapped on a boat without oars or sails carried by a lazy river's flow. It's as scary as it is disheartening.
Temperature is another experience that has him hating his new situation. He finds it amazing that humanity survived at all, given the extremely limited range of temperature that doesn't kill them. He quickly learned than the range in which humans feel comfortable is even narrower and that being placed in conditions that fall within the scope between optimal temperature and deadly temperature causes extremely unpleasant sensations. It takes some getting used to - more than he'd like to admit.
This is why he spends most of his free time cocooned in blankets and the warmest clothes he can find, reading or simply thinking. Luckily, he doesn't have to lay on the floor anymore - they have a bed, a real bed salvaged from one of the camp staff's houses that collapsed and had to be demolished. He hates even peeking out of his heap of blankets, so he's silently grateful to Dean, who doesn't force him to do regular camp chores, as he usually does with people who are sick, but not yet dying.
Cas has also learned that a trifle such as runny nose can gradually become the cause of an excruciating torment. He would feel so much better if only he could find his soft, warm, baggy, fluffy...
"Hey, give me back my sweater!" he shouts at Dean, who has just appeared in the doorstep, bringing a whiff of sharp, clean, frosty air with him. The man looks down at himself, brushing fresh snow off his shoulders and from the patch of blue wool that peeks from underneath his unzipped jacket.
"Since when is this your sweater?"
Cas tilts his head; there is no sign of innocent curiosity in this gesture anymore. He's imbued with Dean's sassiness now, but his rich vocabulary lets him take it to a whole new level.
"Well, I believe I've rightfully owned it from the day you said, quote, It sucks balls just like Emmet in Baldwin High, you can have it, it's ugly as fuck?"
The leader rolls his eyes; his hands wander up to the sweater's collar, but stop halfway.
"All right, smartass. I changed my mind. It's comfy."
"Exactly. It's comfy and fluffy and mine," Cas mirrors Dean crossing his arms and his slightly pouting expression, which is enough for the man to realize he isn't going to win this way. Winchester proceeds to yank his arms out of the jacket's sleeves. The garment wasn't designed to be worn over a thick sweater, so it takes some scrabbling. Clumpy boots, which he tries to shake off, don' let go easily either.
"How come when something is yours, it's yours, and when it's mine it's still ours?" he challenges, still struggling with his left boot, but refusing to bow down and actually unlace it.
"Because, young man, this is how community property works. You said it yourself. I am just conveniently and slyly reversing the perspective."
Dean looks outraged for a moment, but a surfacing memory softens his features. He snorts.
"I said it when you punished my can of taco beef... you can't exactly share chow that's already eaten, you know?"
"All right, I will satisfy your lust for power. Oh mighty Dean, to thee I supplicate, may I please have your sweater back?" Cas delivers a bantering speech, then adds more sincerely: "I'm cold."
"Geez, why do you have to be such a baby?" Winchester carps under his breath.
"Technically I have been human for less than a year, so I think I am entitled to be a little bit of a baby..."
"Technically, Cas, you're a pussy and you know it." Despite his sharp tone, Dean has already given up. He takes the garment off, balls it and throws at his lover, who catches it mid-air.
"I chose to pretend to believe that you have just called me a female cat," a muffled voice comes from inside the bundle of wool Cas is trying to put on, "And thank you for the sweater. It smells like you," Cas adds when he finally surfaces.
"Dude. Seriously. That was gay."
"It's interesting that you mention it now. There's hardly anything more gay than the things we..."
He's cut off by urgent knocking at the door and Dean's taut "Damnit! Cas!" that comes a split second later.
"What?" Cas shrugs with badly faked obliviousness.
"Just..." Dean desperately tries to shush him, which brings a smug smirk onto Cas's face, "shut up and go back to being sick. You're good at it. I'll tell Chuck to find you a sedentary job. I'm gonna tend to the game with the guys."
"Oh, so you really went hunting, as in hunting?" the piece of news is to interesting that the fallen angel forgets to taunt Winchester.
"Yeah. Hunting hunting. I killed Bambi's mom and a couple of bunnies, like it or not," the leader straightens up with pride before searching the coat hanger and improvised shelf for a more comfortable and less valued attire. He settles on an old, dingy flannel jacket and a pair of Wellingtons, which make him look like a thoroughbred redneck, "I'm leaving, so you can sob all you want, but try to check yourself and not look hideous when I come back."
"Love you too, sugar cube!" as Dean's leaving, Cas shouts through closing door as loud as he can, making sure anyone in the range of thirty feet can hear him. Before the door closes, he can make out Dean's peeved 'Ugh'.
Not more than five minutes has passed when the leader opens the door with a kick, carrying a huge cardboard box that he plops onto the floor next to the bed.
"Almost forgot. Check it out," he grins.
"Is it the job from Chuck? Doesn't that knave have mercy?" Cas whines, believing the box to contain loot to collate or all kids of broken gizmos to fix.
"No, it's for you, as in for you," Dean is already by the door, waving good-bye with his back turned at Cas.
The fallen angel doubtfully lifts the lid to peek inside.
The box is full of disposable hand warmers.