A/N: This fic was written for dc_fireplace over at Livejournal.
The first time it happened wasn't so bad because they were alone in the motel room. Sam was already out picking up breakfast and Dean was busy packing their bags, talking to Castiel a mile a minute as he worked.
"I was just thinking that we should probably head back up North. I mean, unless we find something along the way, of course. I'm guessing Bobby's probably getting annoyed with us since we haven't been to see him in almost a month," Dean said as he bent down to pick up a pair of wayward socks. "Do you think-"
A small explosion cut Dean off mid-sentence. His vision filled with black and he tasted something dry and scratchy on his tongue.
"What the hell?" he spluttered, spitting whatever was in his mouth into his hand.
It was a now damp feather.
Other feathers were falling in a swirling circle and at its epicenter was Castiel, eyes on the ground and pale cheeks flushed red. Over his back were two enormous black wings that Dean had only ever seen as vague shadows. But there was nothing insubstantial about the shimmering inky feathers rustling on the wings that somehow made Castiel seem both smaller and larger.
"Cas? Did you just explode?"
"Forgive me, Dean," Castiel said and then he disappeared.
"Okay," Dean said to the empty room. For a moment, he just stared around at the wisps of down floating through the air. Then he started collecting the feathers off the floor. By the time Sam returned with breakfast, Dean had quite the bouquet of feathers fisted in one hand.
"Cas bring you angel flowers?" Sam asked immediately.
"Bite me," Dean said.
He waited until Sam was distracted setting out their pancakes before stuffing the feathers down in his bag.
Cas returned while they were driving down an empty highway and it was good too because his abrupt appearance made Dean swerve into the other lane.
"Cas," Dean snarled. "You got a cell phone. Why don't you use it sometimes."
"I did," Castiel said with the usual head cock of confusion. "How do you think I knew your precise location on this road?"
Sam snickered. "He sent me a text."
"You can text?" Dean asked in surprise, eyes in the rearview mirror.
"It's hardly complicated, Dean," Castiel said in a pretty high and mighty tone for someone who lost control of their wings earlier that day.
"Bite me," Dean said because it seemed appropriate again.
And then there was a blasting sound, the press of warm rough feathers down his collar and he couldn't see. He slammed on the brakes, grimacing when the wheels screeched along the pavement. Beside him, he heard Sam gasping and spitting and for some reason, Dean felt uncomfortable with Castiel's feathers being in Sam's mouth.
"Cas?" Dean asked, reaching up to brush feathers off his cheek. The coarse texture sent a cascade of shivers down his spine.
"I'm...I'm sorry," Cas stuttered. Which worried Dean enough that he flipped around to get a look at him, but by the time he turned, Castiel was gone.
"What the hell was that?" Sam said, plucking a small feather out of his hair.
Dean snatched it out of his hand and shoved it in his front pocket.
"Man's got hair trigger wings," he grunted and then put the car back in drive.
Dean could ignore exploding wings twice. But after the next four times, Dean started to wonder. Well, in truth, he started to worry. If this wing thing was a result of Castiel's dwindling powers, Dean was afraid Castiel would eventually be unable to keep them inside his vessel. Which would make moving within human society without questions difficult. And embarrass the shit out of him because every time the wings made an appearance, Castiel stammered, turned bright red and disappeared.
They were lucky it hadn't happened in public yet. The third time happened in the parking lot of an abandoned movie house while Dean was telling the story about the double-jointed waitress in Miami. The fourth in the middle of an open field when Dean was busy cleaning mud off his bare chest with the shirt that'd been ruined by a werewolf he'd just killed. The fifth woke Dean from a dead sleep in Bobby's living room. The sixth in their motel room as Dean was coming out of a shower.
When that last explosion nearly knocked the towel off his naked body, Dean decided to really start investigating.
Asking Castiel was out of the question. The merest mention of his wings or feathers or even the odd comment Sam made about birds on an electric line made Castiel fidget and leave immediately. Dean tried to show Castiel his growing collection of loose feathers to demonstrate the severity of the situation, but Castiel just exploded a seventh time and vanished.
Bobby researched under protest, but there was barely information about the real existence of angels, much less creepy angelic side effects. Sam was just as helpless, but adamant they do something because he couldn't handle eating any more angel feather fluff.
There was really only one option. Dean hated doing it, but they'd seen the guy a couple of times since the TVLand debacle and he'd almost come around to not wanting the Winchesters to be vessels anymore.
So Dean did the stupid summoning spell and waited impatiently in his empty motel room for Gabriel to show his ugly mug.
"Now this is unusual," Gabriel said from behind Dean. His smug voice sent douche chills up and down Dean's back.
"Yeah, yeah, I called you. I need your help. Blah blah superior self-righteous prick blah," Dean said as he turned to face the archangel.
"You don't ask for help very often, do you?" Gabriel said. He flicked a hand to the side and sat in a giant golden chair that appeared out of nowhere. "You may approach my throne."
"Fuck you," Dean growled.
"Ah, so you haven't done this asking thing before," Gabriel said in apparent delight. "See ya."
"Wait," Dean called, hating himself and Gabriel in equal measures, but unwilling to let this one chance to help Cas slip by.
"What's this I hear?" Gabriel put his hand up to his ear and Dean really wanted to punch him.
"Wait, please," Dean ground out. "I need your help. It's about Cas."
A flicker of actual concern lit in those fickle alien eyes for an instant. It was gone when Dean looked closer, but Gabriel couldn't fool him. Dean now knew that he actually did give a shit about his brother. The tightly clenched knot in his chest relaxed.
"What about him?"
"It's his wings. Or his feathers or something. I don't know, man. They keep...popping out of his body," Dean explained worriedly.
He didn't expect Gabriel to start laughing.
"It's about time," he said through genuine chuckles. Dean narrowed his eyes.
"Time for what?"
Gabriel stood up from the chair, which melted into nothingness and placed his hand on Dean's shoulder.
"Our little Castiel is finally becoming a man," he said.
"What?" Dean said and then because it felt necessary, he added, "What?"
"Hey, we're angels. It takes us a little longer to get to puberty than humans," Gabriel said, full of mirth.
"Puberty? You guys have puberty?"
"Sure! God, I remember when Michael was going through it. Just the slightest wisp of passing cloud against those big silver wings and he filled the Heavens with a fuckload of feathers," Gabriel recounted, laughing so hard he had to rub tears away from his eyes.
Dean didn't find this quite as funny as Gabriel.
"Is he going to be okay?" Dean demanded. "It seems like he hates it or something."
"Oh and what, you enjoyed puberty?" Gabriel asked. "Come on, man. Tell me, what exactly was going on all those times Castiel went off, huh?"
"Well, it was..." Dean trailed off as the memories hit him. Bending over to pick up socks. Telling Cas to bite him. Talking about fucking some waitress. Sopping mud off his naked chest. Waking up to see Castiel staring at him. Walking around in nothing, but flimsy towel. And then bringing Cas' attention to the problem, shaking a fistful of feathers in his face.
"Are you telling me that I've been giving Cas inappropriate wingrections?" Dean asked slowly.
"Mazel Tov, Dean. You're an angel's wet dream," Gabriel said. Then he clapped Dean's shoulder again and shifted into flight.
Dean immediately tugged out his cell phone and called Cas. As soon as he answered, Dean growled into the phone, "Get your ass here right now."
There was the sound of exploding feathers on the other end of the line.
Dean rolled his eyes and snapped the phone shut. Castiel appeared, looking flushed. His wings were still out, puffy and agitated on his back. Dean poked him in the chest.
"Were you ever going to tell me you're a pre-teen angel?"
Castiel jerked back, probably about to escape again, but Dean grabbed his arms.
"Oh no you don't, Doogie," Dean said, holding Castiel tight. The wings fluttered and thrashed and suddenly Dean realized how fucking awesome this whole thing was. Those wings were out and restless because of him. Because of Dean fucking Winchester, Castiel couldn't keep himself under control.
Holy shit, that was hot as hell.
"What happens if I do this?" Dean asked, his voice surprisingly shaky. He reached over Castiel's shoulders, closely watching Castiel's face, cataloging the way Cas' eyes dilated, the way his lips parted and his head fell back when Dean's fingers buried in the inky black feathers.
"Dean," he whimpered and that was it. Dean pushed Castiel back against the bed, smiling when Cas landed in a soft pile of his own feathers. He whimpered again when Dean straddled his lap and started some hardcore grooming.
"This is going to be the best puberty ever," Dean said happily.
There were two more explosions that night, but Dean didn't mind them one bit.