SPOILERS for last night's episode 11 x 10 (The Devil in the Details).

With that out of the way...what the hell? Maybe I'm slow, but I did NOT see that coming – I've been too busy freaking out on Amara for claiming a bond with Dean. He's already bound, bitch! I've been obsessed with the idea that Cas will get between the two of them at some crucial moment, breaking the bond Amara thinks she has on Dean, spoiling whatever she needs him for. Yes, I know I need to let it go, but my shippy little heart can't help it.

But I digress. Woke up in the ass hours of the dawn and needed to write this down, so hopefully it's not too incoherent. Destiel...ish.

This takes place shortly after the end of 11 x 10.

Disclaimer: Supernatural doesn't belong to me. For real. Didn't I just say I didn't see last night's events coming? If it belonged to me, I'd have known.

Dean jerked awake, fumbling on the nightstand for his loud-ass phone. His other hand had already found the knife he kept under his pillow.

"Mmhllo?" he mumbled.

"Dean." Cas's voice on the line finally broke through the fog of sleep in Dean's mind.

"Cas, hey," he said, returning the knife to its hiding place and then rubbing his eyes as he sat up. "You okay, man? Sam and I were kinda worried. Where are you?"

"I'm here, actually. I'm at the bunker. You going to come let me in?"

Dean rolled out of bed and shrugged his robe on over his T-shirt and boxers. He groaned as the beating he'd taken from Lucifer made itself evident. "Yeah, hold your horses, I'll be there in a sec." Cutting the connection, Dean dropped his phone back onto the nightstand and stepped into his slippers.

He shuffled through the bunker, yawning massively as he went. Had he even managed two hours of sleep before Cas came a-calling? He snorted. Of course not. That would be too much to ask.

Tromping up the iron staircase, Dean yawned one last time as he unlocked the door for the angel. One of these days they were just going to have to figure out how to duplicate the frickin' key so Cas could have his own. He pushed the door open and turned to limp his way back down the stairs. "Come on in," he growled.

Since he was up, he might as well start some coffee. Heading for the kitchen, he tossed his question over his shoulder to Cas who trailed behind him. "So, how you doing, really? Getting your ass handed to you twice in one day can't be good for the old ego."

A hand clapped down on his shoulder and spun him around to face the angel. Dean held up his hands in front of him. "Whoa, jeez! I was just kidding. Don't get your panties in a bunch."

But Cas just looked at him with a weird as hell look on his face and one hand gripping the robe at Dean's shoulder. With a rather disturbing gleam in his eye, Cas turned them and shoved Dean back against the wall of the corridor.

"Hey! What're you-"

He was cut off mid-sentence when Cas's mouth slammed into his. After an initial instant of utter shock, Dean shoved him away. "What the hell do you think you're doing?"

Cas's head twisted to one side and a smirk graced his lips – the lips that had just been all over Dean's. "You know, Dean, I've been thinking. What with it being the end of the world and all, we might as well...enjoy it."

He stepped closer again, pressing Dean to the wall with his hands on Dean's hips.

"Are you kidding me right now?" Dean felt like his voice had jumped an octave, but who could blame him for that? "Cas, what the hell?"

"Mmm. Right you are." The smirk widened and Cas's eyes raked up and down his body. Dean suddenly felt super exposed in his robe and slippers. Cas's voice was oddly musical as he crooned, "You can't tell me you haven't thought about it."

"I-" Well, of course he'd thought about it. Who wouldn't? But that didn't mean... He wasn't... "Cas, I don't-"

He was floundering, and Cas could tell. The angel surged forward, catching him in a scorching kiss, and where the holy hell had he learned to do that? Dean found himself unable – or unwilling – to pull away as Cas kissed him, his tongue delving deeper with every pass. When Dean's hands flew up to clasp the sides of Cas's face and pulled him closer, Dean knew he was screwed.

Yeah, he'd thought about it. More than he'd ever admit, even to himself.

End of the world. Maybe Cas was right about that, he thought as he kissed back. Who knew how long they had until they were all freakin' dead? He clutched at Cas, desperate now to drag him closer.

He felt Cas's mouth stretch into a smile, and when the first bark of laughter broke free, Dean pulled back, confused.

"Ohhh, Dean," Cas drawled between gales of laughter. He even wiped a tear from the corner of his eye. "I can't do it, even for the laughs. You're too easy."

"What? What the hell, man?" Dean shoved Cas away and backed down the hall a few steps. Anger and humiliation burned hot in his cheeks. "Is this supposed to be some kind of a joke? It ain't funny, asshole!"

"No, no...well, yes, but you're only hearing half the punchline." Cas smiled widely, teeth and all, and pointed at his own head. "You should hear what's going on up here."

"What?" Dean snapped. But a cold, creeping dread started in the pit of his stomach. No. It wasn't possible. Was it? He dropped to a whisper. "Cas?"

"Dean, Dean, Dean," Cas shook his head and clucked his tongue. "A few fries short of a Happy Meal, aren't you?"

"Lucifer," Dean choked out, the nausea from the smiting sickness rising up again.

A twisted expression of glee crossed Cas's – Lucifer's – face. He threw his hands up in the air. "We have a winner!"

"You son of a bitch!" Without another thought, Dean launched himself at the angel, but before he could get close enough to so much as take a swing, Lucifer waved a hand and sent him flying down the hall to crash into the door at the far end.

The back of Dean's head cracked sickeningly against the door and he slumped in a limp heap to the floor. Pain swirled in flashing white lights behind his eyelids, and by the time he managed to pry his bleary eyes open, Lucifer was there. He stood over him, feet on either side of Dean's legs.

Lucifer crouched down, peering into Dean's face with Cas's eyes. It was so wrong, Dean felt sick. Or maybe that was the head injury.

"Don't worry, Dean. I need Cas alive. And I still need you and your brother. I'm not going to kill you. And this bunker..." Lucifer let out a low whistle and glanced around as if he could see the whole thing through the walls of the corridor. Hell, maybe he could. "I think I'm gonna move in, be roomies with Sam again. What do you think?"

"Screw you," Dean spat, the words slurring together.

Lucifer patted Dean's cheek and gave him an indulgent smirk. "Maybe later, sweetheart. Castiel deserves a treat for letting me in, I suppose. But right now, I've got the Darkness to kill. And maybe a few billion people. Whatever." He shrugged and reached two fingers toward Dean's forehead. Dean tried to pull away, but he could barely turn his head.

"What? I told you I'm not going to kill you." Lucifer snorted, as if Dean had utterly insulted him. "Fine. Stay concussed. See if I care."

Lucifer stood again and grinned down at Dean with Cas's face. Blackness swirled in on Dean's vision as he fought and failed to stay conscious. As he sank into oblivion, the last thing he heard was Lucifer speaking with Cas's voice.

"Oh, and Dean? That whole 'not going to kill you' thing? I was just kidding."