**I don't own Supernatural, much to my chagrin. All of this is my imagination combined with Supernatural's characters. I hope you like it!**

More than anything, purgatory was cold, bitterly so. In the moments Dean and Castiel managed to evade purgatory's monsters, they would seek out a place of refuge for Dean to sleep in as Castiel guarded. Every time Dean was trying to fall asleep in the terrible cold, Castiel would offer his coat for warmth, and Dean would stubbornly refuse. Eventually Dean's body would succumb to sleep despite the cold, and Castiel would immediately lay his coat over him, almost instantly stopping his shivering.

The first time Dean woke up to find himself curled up beneath the coat, he sighed and stood up with the coat, returning to Castiel wordlessly. The next time Dean had a chance to sleep, he would again insist that he didn't need the coat and end up waking up underneath it.

Castiel knew that despite Dean's protests, he wanted the coat, because it was incredibly cold. The temperature didn't bother Castiel, but he could tell that for a human, it was too cold for comfort.

On the rare, quiet nights, Castiel would sit next to Dean as he tried to sleep, always a foot away as Dean insisted. But within a few minutes- and Castiel wasn't sure if Dean was ever asleep by then- Dean would roll closer and curl into Castiel's side, a pleased hum eitting from him as he wrapped himself around Castiel's warmer body.

The first time it happened, Dean had woken up slowly, confused by his unusual warmth. Then he had glanced up and seen Castiel and realized that their legs were intertwined and that his head was resting on Castitel's stomach. As soon as he realized, he jumped up, muttering about checking the perimeter.

Castiel watched him march around gruffly, knowing that despite his tough-guy act, he would end up the same way the next time he slept next to Castiel.

Quiet nights were few and far between- Dean only slept in small increments for a long stretch of time, and the increments weren't very common either. Castiel was always patrolling during these short sleeps, and after weeks of fitful, brief sleep, Dean was beyond exhausted.

Finally, a quiet night allowed them to find a small cave, and Dean fell asleep in seconds, Castiel sitting beside him for the first time in weeks. It took only moments for Dean to gravitate towards Castiel in the dark cave, and as Dean strung himself around and over Castiel, his head in Castiel's lap, Castiel couldn't help but wonder what would happen if an attack came them- he'd get trapped in Dean's clinging arms and legs. But the look of peace on Dean's face that he hadn't seen in weeks prevented him from shifting away from the sleeping man.

Six months passed in purgatory, and towards the end, it was eerily quiet and empty, so nearly every night they would lie together as Dean slept. Dean even stopped leaping away in the morning, he would just disentangle himself from Castiel and lie next to him, their sides pressed together until one of them finally stood up.

They were finally liberated from purgatory by some mystery person and brought back to the real world to find that three years had passed.

Sam was still alive, albeit different- stronger. He welcomed them back, crying a little upon the reunion. There were still things to deal with, and they dealt with them together. Castiel would occasionally consider leaving them alone, as he thought they should be, but Dean would see the contemplative look on his face and demand that he stay with them.

The first night back in the real world, Dean found that he couldn't sleep. It was strange, to be unable to sleep in a warm, safe bed in a motel away from monsters. After trying to sleep for an hour, Dean got out of bed and left the motel room, glancing at Sam, who was sleeping in the other bed.

He headed straight for the car, climbing into the back seat. Castiel was sitting on the other side of the seat, staring at his hands.

"You should sleep," Castiel said. "You must be tired."

"I can't," Dean said truthfully. "And I figure it's better to wait out the night in the car than to toss around in my bed and risk waking Sam."

"True," Castiel said. "But you should still try to sleep."

"I have been trying, I can't."

Castiel turned to him, blinking. "I don't understand."

"Me either," Dean said. "But I'm not that tired, so I don't really care."

Castiel watched Dean as he leaned into the seat, closing his eyes. It made him smile when a few minutes later Dean's head slumped to the side, revealing that he'd fallen asleep.

His head slipped down across the seat and onto Castiel's shoulder, and Castiel sat still, doing his best to keep the tired man asleep. Sam woke up panicked in the morning, finding Dean's bed empty and the sheets tangled, but calmed down when he ran outside and found him sleeping on Castiel's shoulder.

Sam found it a little strange that his brutish brother, who considered that kind of contact 'wimpy', would be leaning on the angel, but he didn't mention it. He simply returned to the motel room and waited for Dean to enter. Castiel hadn't noticed Sam in the parking lot, so it took a while, as Dean was a moderately heavy sleeper.

Dean entered by himself an hour or so later with a box of donuts, claiming that he'd just gone out to get some. Sam smiled slightly at the lie, but didn't comment.

Castiel was still waiting in the car when Sam and Dean finally went out to leave, and Castiel didn't comment either. The next time they stopped at a motel, which was after two nights and three days of being awake for the sake of a case, Sam told Castiel he was welcome to wait on the couch in the room rather than the car outside, thinking that forcing him to sit in the car was a little rude.

Castiel blinked a few times at the offer and glanced over at Dean, who was practically swaying on his feet from exhaustion. He nodded, following them into the motel room and planting himself on the couch. Both of the Winchesters went to their respective beds almost immediately, Dean barely sparing time to kick off his shoes whereas Sam showered and changed into sweatpants first.

When Sam fell into his bed, he noticed that Dean was still awake, staring up at the ceiling with bloodshot, tired eyes. He fell asleep before he could worry about it too much.

Dean lay awake for an hour before he finally sat up, staring across the small room at Castiel, who was sitting uncomfortably on the couch. Dean swallowed hard, not liking that he had to ask for help, especially in this manner.

"Cas," Dean whispered, hoping not to wake up Sam. Castiel looked at him immediately, standing up silently.

"What is it, Dean?" he asked, standing beside his bed.

"I can't sleep," Dean said, feeling like a child.

Castiel gazed at Dean for a long, somewhat uncomfortable moment before going around to the other side of the bed and sitting down, leaning against the headboard. Dean looked over at Castiel, glad that the angel had understood without him having to say anything aloud.

It took moments for Dean to fall asleep then, and Castiel was quite amused by how quickly Dean managed to curl around him, one leg shifting free of the blankets to tangle itself with Castiel's legs.

Both of the Winchester slept for a long time, obviously having been sleep deprived, and Sam happened to wake first, immediately noticing the fact that there were two people in the other bed.

He raised his eyebrows at Castiel, glancing down at Dean, whose body was thoroughly wrapped around Castiel's. Castiel looked back at Sam for a moment before looking down at Dean's relaxed face and deciding that this was a good thing.

Sam couldn't help but wonder if something…more had developed between his brother and Castiel while they were in purgatory, but he dismissed the thought. It didn't really matter. He had his brother and his friend back, and that was what mattered. He would probably ask, though.

Sam got dressed and left to get some kind of breakfast, and despite the noise of bags zipping and the bathroom door closing, Dean was still not awake by the time he left.

He returned with a bag of donuts a while later to find Dean still asleep and still intertwined with Castiel, so he averted his gaze and dropped the bag on a small table, taking food for himself and sitting on the couch rather awkwardly.

Castiel leaned down slightly and whispered something to Dean, finally waking him. Dean sat up slowly, drawing away from Castiel with a yawn. He rolled off the bed with a loud thump and stumbled over to the donuts. Castiel moved to sit at the end of the bed instead, and nobody said a word for a long time.

Sam cleared his throat after a long silence. "Just, uh, curious," he said. "Is there some kind of…relationship I should know about?"

Dean looked over at his brother with alarm in his eyes. "What?" he asked, an incredulous look on his face. "Why would you ask that?"

"Dean." Sam said. "You were practically on top of Cas."

"So?"

Castiel sat silently throughout the conversation, looking down at the floor.

"So, you don't do that with someone who's just a friend."

Dean huffed and shoved on his shoes. "Don't we have something important to do today, more important than this stupid conversation?"

"No," Sam said, shrugging. "We've got nothing going on."

"I'm sure there's some murder, some disappearance that looks like our kind of thing."

"No, not at all," Sam said. "We have nothing to do today."

"I think I'm going out, actually," Dean said. He stormed out of the motel room, slamming the door rather loudly. Castiel stood up, giving Sam a confused glance before following Dean out.

Sam stared after them, the glance from Castiel confusing him more than anything else.

Castiel caught up to Dean as he was rounding the corner to the parking lot where the car was.

"Dean!" he called, watching Dean's spine stiffen as he slowed to a normal paced walk before stopping at the car.

"What is it, Cas?" Dean asked gruffly.

Castiel realized he didn't quite know what to say in this situation, so he simply leaned against the car, crossing his arms. Dean stood a few feet away, his arms crossed similarly.

"What is it?" Dean asked again.

"You shouldn't have stormed out on your brother; he'll probably worry if you disappear off somewhere."

"I don't really care."

Castiel stared at Dean, noticing that he was breathing heavily despite not really having exerted himself.

"Why are you so angry at your brother?"

Dean looked away, rolling his eyes. "Because he's stupid."

Castiel frowned. "He's not particularly stupid."

"Cas," Dean said. "Can we leave this alone, please?"

"I'm curious."

"Curiosity killed the cat, Cas, just drop it."

"I don't want to 'drop it'; I want to know why you got so mad at Sam."

"Drop it."

"I'm not going to drop it, I told you, I'm curious!" Castiel exclaimed. "I don't understand why you won't tell me why you're angr-"

Castiel was suddenly pressed into the side of the car, his back arching against the rounded angle of the side. Hands pressed against his arms roughly, fingers curling into his coat tightly. Dean's body was pressed against his, and Castiel could feel Dean's chest as he breathed. Their faces were close, not touching for just an instant before Dean pressed his lips to Castiel's, surprising him for a moment before he started pushing back into Dean, his hands finding purchase at Dean's back in the fabric of his jacket.

The soft noise Dean made when Castiel's hands grasped his back was interesting, and Castiel broke off from Dean for a moment to move down to his neck, sucking and biting at the skin there. Dean made another noise, this one lower, almost a moan, and his hands gripped less tightly against Castiel's arms as he shifted his head up to expose his neck more.

Castiel twisted them around so that he was pressing Dean into the car, and the movement caused Dean to let out a quick breath. The car was fairly low, so Dean's head rested almost on top of the car, making his whole body arch out slightly to accommodate the angle. Castiel pressed harder into Dean, moving back up to his mouth, pushing into the man to relieve this tension between them that he hadn't really known was there.

That was how Sam found them, moments later- Dean pressed up against the car, rather heatedly kissing the angel he'd denied having a relationship with.

Sam cleared his throat, prompting Castiel to step away awkwardly.

"So, you're just friends, huh?" Sam asked, raising his eyebrows at Dean.

Dean glared and touched a hand to his reddened lips, still breathing heavily. "Not exactly," he said, licking his lips absentmindedly.

"Good to know," Sam said. "By the way, we're getting two rooms next time."