There was a brief moment of confusion as Cas hugged him, nearly bowling him over in the process. "Whoa, Cas, calm down! You got more muscle than I'd like to admit, don't tackle me like that..."
Sam smirked over Dean's shoulder. "He's delicate," he mouthed to Cas. He threw his jacket over the back of one of the chairs and snuck off to the kitchen to make himself a health shake.
Dean, having been in the angel's embrace for much too long, began to get restless, and when Cas didn't seem to take the hint, he pushed himself away. Clearing his throat and yanking his shirt down – it had risen above his waist when Cas had thrown himself at Dean – he stepped back to a more comfortable distance and said, "Sorry for, uh... Making you face off against Lucifer." He laughed nervously.
"It's fine, Dean, I know Sam is what's important, and everything else is secondary." His reply carried a distinct bite to it, and passive aggression didn't seem to cover it.
Scowling, Dean challenged, "No, Cas that's the problem; I left you to fight the damn devil while I sat back and only helped at the last second. I know Sammy is my weak spot, but that doesn't excuse that fact. We could've lost you, Cas." Unable to hold Cas' unwavering, piercing gaze for any longer, Dean pulled out a chair and sat down. He already felt guilty for all he had put Cas through in the last few months, and Cas had put all other pressing matters aside to come to his aid; he owed him the same courtesy.
Instead of taking the chair opposite Dean, Cas climbed onto the table and sat, his legs crossed, hands folded in his lap. "You know, Dean, sometimes I feel like I'm the only one really trying in this relationship." Dean's raised eyebrow made him feel giddy. "Oh, like you didn't notice! The only time you call me is to ask a favour. I never get a break! But you– you get to go hang out with Sam and hunt, do your job, a job that you enjoy doing all day, every day. And when you're not rescuing imaginary friends, you're kicking back with a couple of beers watching Game of Thrones. Sure there are some hiccups, but you're never alone. Do you think I like this job, Dean? You think I like being kicked out of here because some renegade angel who threatens to kill your brother told you so? Who comes along with me, to watch my back?"
Dean sat in stunned silence, completely incapable of formulating a response to Cas' sudden outburst. One thing that disturbed him more than the words, however, was the smile. The pleased smirk that Cas wore on his face. The words, he knew to be true, but the smile was strange, out of place. It didn't fit them at all. "Cas..." Dean started weakly, "Cas, I know you're mad. You have every right to be... I can't ever make it up to you, and I know that, but you've got to understand, buddy, we care about you just as much as each other. Family always comes first."
"But I'm not family, am I Dean? I'm not even the same species as you and your brother. Why should you care about me when I'm just your invincible, angelic messenger boy?" He laughed, but it was cold and humourless. "Dean," he growled, "You can't explain away that guilt. You can't make excuses for everything, and you most certainly cannot make it up to me by telling me that I'm like family. Because I know I'm not. Would you pick me over Sam?"
Hesitating only a minute, Dean replied, "You..." He gulped, "You both mean so much to me, Cas, I– how can I choose...?" He hung his head, determined not to let Cas see the tears welling up in his eyes.
"Copout!" Cas shouted, a slight lilt to his voice. He was enjoying this. "Come on, Dean, we both know the answer to that question. You'd save Sam, no doubt, again, and again, and again, until you two are the last people alive on earth." He smiled widely, showing teeth, and leaned in close, "Codependency isn't something to be proud of, you know."
Finally, Dean couldn't handle any more, and launched himself over the table at Cas, yelling and screaming, tears now streaming down his cheeks. "How could you say this to me?!" He yelled, pinning Cas' wrists down on the table. "You mean just as much to me as Sam does! I– Cas, you son of a bitch!" He raised his fist, preparing to throw a punch right to the side of his face. But he couldn't do it. Not after all that Cas had told him. He was right, and he knew it.
And with his moment of hesitation, Cas took hold of Dean's raised fist and held it under him. Now he was the one in control. Cas could feel Dean's pulse in his wrists; elevated. He sat on Dean's stomach, and leaned in close. "Will you pick familial love; or your lust for this pretty boy angel?"
He pushed himself on Dean, initiating a furious, angry kiss that only a complete sadist like Lucifer could enjoy. But it did serve its purpose. He was kissing Castiel. Feelings that he had been repressing for years finally allowed themselves to surface, and he tried to reciprocate it, fighting back, but also trying to include every unspeakable emotion that he had been holding in. His hand, broken free of Cas' grasp, grazed the angel's stubble, and settled on his cheek. Though not the greatest of circumstances, he couldn't deny that it was a relief to get the feelings off his chest.
"Aghh–!" Dean reeled back and hit his head on the table. He felt his lip – it was bleeding. "The hell was that for?!" Dean muttered, feeling his cheeks flush.
He looked up at Cas to see him staring down at Dean as if he was a fly caught in a particularly nasty spider's web. "I believe," he started, wiping his mouth on his sleeve, "that was your precious Castiel fighting back. He does seem like the type that would bite."
Dean's eyes widened. Lucifer – for it was only now that Dean's suspicion was confirmed about who he'd really been speaking to – smiled down at him. Now, it was a distinctly cold and very un-Cas-like one. Not an ounce of his Castiel was left in the devil's angelic vessel now.
"Huh," he took his eyes off Dean for an instant – for dramatic effect, he was sure. "I always took you for the more fiery, intense, one night stand kind of guy... But apparently not." He turned his eyes back on Dean, searching him for any kind of visual giveaways that might suggest a pressure point weakness. Sure enough, Dean's eyes flicked towards the kitchen. "How do you think Sammy would react to this? Hm? I bet he wouldn't even be surprised. You do know you're excruciatingly obvious, right? How would he feel if he found out about the tender feelings his brother has for an angel? I bet he'd like to watch; you know, he couldn't take his eyes off of Mikey and I when we'd fight in the cage."
Dean struggled to get his other arm free, but Lucifer simply knelt on his arm and clicked his tongue in annoyance. "Oh Deanie, Deanie, Deanie... Don't you know it's rude to interrupt when someone's speaking?"
"What did you do to Cas...?!" Dean's anger was making him reckless, but he knew he had to keep Lucifer talking, otherwise he was sure it would turn physical again.
Lucifer gave him a wide smile. "Oh, like you'd care anyways. Clearly you only like him for his body." He chuckled. "Has he shown you his true form? He is quite ugly, especially by angelic standards. And don't go telling me that you like him for his personality, because I'm an asshole, and you kissed me all the same." He put his fingers around Dean's neck and slid them up through his hair, to the top of his head. He nearly giggled with glee when Dean shuddered and tried to pull away.
Dean could feel Lucifer's fingertips digging into the top of his head, and he winced in pain. "What did you do to Cas...?" He repeated, his fists clenching under the increased pressure on his wrists."
"I could split your skull open right now, with my bare hands."
"WHERE THE HELL IS CASTIEL?!" Dean yelled, his voice wavering slightly. He had broken the unspoken rule between them of not tipping Sam off what was going on.
When Lucifer spoke again, the anger was apparent in his voice. "Oh, he's in here. Let me in of his own free will. I told him I'd kill the Darkness. Again." Lucifer lifted a hand off Dean and tapped his own head. "Hey Cassie, do you want to come out and play?" His face looked blank for a minute, and then finally he waved, smirked, and Cas' face morphed into an expression unlike anything he had ever seen before. "Dean."
Cas hurriedly got off of Dean and watched as he sat up. He refused to meet Dean's eyes, but after they had gotten to their feet, he placed a hand on his shoulder, slouched ever so slightly and rested the top of his head on Dean's chest, exhaling slowly. "I am so sorry, Dean."
Dean somewhat robotically wrapped his arm around Cas' back. He was still in shock from everything he had just been told. It was a mixture of anger, disgust, surprise, and fear. But he knew that Cas was just as in need of comfort as he was; probably even more so.
"I didn't want any more trouble for you or Sam. I thought... Maybe if I were the one to accept Lucifer instead of Sam... He would leave you two alone..." Cas hunched his shoulders and gently fit his hands around the back of Dean's neck.
When he looked up, Dean caught his gaze at last. His blue eyes were wrought with guilt and self-loathing. Both were familiar to the older Winchester. He tilted Cas' head upwards, and caught his lips in another kiss; only this time, he knew that both of them were in control of their bodies, and their feelings. It was no longer a hateful act, repulsive and unwanted. It was a goodbye.
Dean's eyes flicked open suddenly; he noticed Sam standing at the entrance of the room, dumbstruck, with a plate of food in one hand and a glass in the other – but he wasn't worried about Sam finding out anymore. "Cas, you can't– we can help you!"
His arm was forced off, and the loss of warmth on his neck made him shiver involuntarily.
Cas turned quickly to face Sam. "Pathetic, isn't he?" His tone was cold, and it didn't take an expert to know that Lucifer had taken back control of Cas' vessel. Dean wasn't sure if the comment was directed towards himself, or Cas.
Halfway through a peal of loud, hearty laughter, Cas took back control of his body, and, sounding strained, said, "I won't make any more excuses for what I've done... But I never intended for any of this to happen. Please forgive me." And with a flap of invisible wings and a flurry of wind and papers, he was gone.
Dean sank to his knees, and Sam rushed over to him, the plate and glass he had been holding, now laying in pieces, smashed on the floor.
The Winchesters had lost their closest friend to the devil, and not for the first time, neither of them had even an inkling of an idea of what to do next.