Note: Contains spoilers for Season 5. I do not own Supernatural or its characters, this is merely a fanfiction.
Castiel grips the handle above the car door and stares, terrified, out the front window of the old '67 Impala as Dean drives ferociously towards the old graveyard where he knows his 'brother' will be. Looking over at Dean, Cas can see the muscles in his jaw clenching as he drives. Cas knows better than to say anything when Dean is like this but he is silently willing him to slow down, lest they crash.
Suddenly, Dean slams on the brakes and turns the wheel hard, throwing Cas into the centre console and almost into Dean's lap. He mutters a quiet "Sorry" as Cas rights himself back in his seat. Jumping up the kerb and into the gates of an old decrepit graveyard, Dean brings the Impala to a surprisingly gentle stop in front of 'Sam' and 'Adam'. Dean gets out of the car with controlled grace, trying his hardest to remain calm for his brother. He knows Sam is still in there somewhere, crushed beneath Lucifer's control of him.
Castiel stays in the car as Dean attempts to talk to Sam; their voices are quiet and muffled from inside the Impala. Michael (Adam) starts to move towards Dean. Cas can see his lips moving but can't make out what he is trying to say. Cas gingerly reaches into the back seat and grabs the bottle of Holy Oil the boys kept in the car, he quickly grabs one of Dean's old T-Shirts and stuffs it through the small opening of the bottle, stepping out of the Impala.
As Michael makes a sudden move for Dean, the only line Cas can think of to get his attention in his moment of haste is, "Hey Ass-Butt". Castiel lights the strip of shirt hanging from the bottle as Michael turns on him. Throwing the flaming bottle right into the centre of Michael's chest, it burns his vessel before blasting him somewhere unknown.
"Castiel did you just Molotov my brother with Holy Fire?" Lucifer demands
"Uhhh….. no." Cas stutters
"No one dicks with Michael but me" Those are the last words Cas hears.
...
Lucifer snaps his fingers and Cas bursts into a pile of guts. Dean stares from what was his best friend to Lucifer, mouth agape. He zones out as Lucifer starts talking to him again, and then suddenly Dean is on the bonnet of his precious Impala, a sharp pain in his left cheek; the combined, mortal, strength of Sam and the ethereal strength of Lucifer knocking him backwards. Lucifer pulls Dean roughly off the bonnet of the car, throwing him to the ground. Dean scrambles backwards, pulling himself up to lean on the side of the Impala, trying to regain his bearings. Lucifer is in front of him in an instant, punching him repeatedly, opening deep gashes all over Dean's face. As he begins to lose consciousness, sliding down the side of the Impala, Lucifer stops his senseless beating, staring through the car window. A thousand memories flash through Sam's mind and he regains control of his own body. Startled, Sam quickly takes the 'key' out of his jeans pocket and throws it on the ground, muttering the incantation. The cage opens. Sam turns to say his final goodbyes to Dean, but instead sees Michael. Wrestling with Sam; Michael tries to pull him away from the Pit and close the cage, Lucifer also wrestles with Sam, in his mind, trying to regain control. Sam is able to pull Michael backwards, flailing as they fall into the pit.
…
Castiel blinks back into existence disorientated, his first thought being of Dean, has he survived Lucifer's fury? And then he sees him, kneeling on the ground with the Key Rings in his hand. He's done it. Castiel walks quickly over to Dean's quivering form and realises that he is crying, Cas puts a gentle hand on his shoulder and Dean looks up at him in utter surprise and relief. Castiel touches Dean's face and heals the deep gashes and puffy black eye he had acquired during the fight.
Cas slowly helps Dean to his feet, only to have Dean collapse on him in a fit of tears, some of joy, most of pain. Castiel stands awkwardly trying to comfort the grown man in this moment of weakness, although he feels honoured that Dean would show this type of emotion in front of him. As Dean regains his composure, he stares hard at Castiel.
"How did you come back from that?" he asks gruffly
"I really don't know." Cas replies with a shrug
"Well I'm glad you're back" Dean says, awkwardly hugging Cas once more.
The car ride back to Bobby's is mostly silent for the two men; the only noise is the hum of the engine. Out of nowhere Dean slows to a stop on the side of the road and cuts the engine. He turns to Castiel and for a moment he says nothing. Cas looks over at Dean to see an inquisitive, adventuring look on his face. Castiel feels himself being drawn to Dean in the strangest of ways; an aching starts deep down in his gut.
"Cas, about back there…" Dean starts
"It's alright Dean," Castiel interrupts. "I understand. You've just lost your brother"
"Oh, well, uhm… okay then" Dean stutters.
They stare at each other in silence for a while, neither of them moving. Dean decides to break the silence. "Uhh hey Cas," He starts, looking down at his lap nervously. "Uhh," he starts again. "C-can I try something?" he stutters; a bit more confidence in his voice than of that in his eyes.
Castiel says nothing, only gives a very slight nod in response, so slight that if Dean had not been watching him with such intensity he may not have seen it. Dean cautiously leans in towards Cas and gives him a light peck on the lips. Stunned, Castiel freezes and Dean stutters out a "S-sorry, I don't know what I was thinking."
As he moves to turn the car over and start driving Castiel stops him with a gentle hand over his. "There is no need to be sorry Dean." Cas whispers. Dean stares at Cas in bewilderment. "I- uhh… I kind of liked it" Cas stutters, looking down in shame.
Dean lifts Castiel's chin with his index finger, giving him a slight smile before kissing him again, this time with more force. Castiel, although shocked at first soon melts into it, kissing back with equal passion.
Breaking the kiss, Dean gestures to the back seat of his Impala. Cas climbs over between the driver and passenger seats and sits awkwardly in the back, while Dean follows. Kissing Cas again, Dean slowly lies them down in the back seat, climbing on top of Castiel and straddling his waist. Dean breaks the kiss to take off Castiel's trench coat, shirt and tie, as well as his own. Dean trails his hands over Cas' hard chest and stomach as he leans down for a kiss once more.
A sudden rustling noise has Dean breaking the most passionate kiss he has ever shared. Looking up, Dean gasps at what he sees. Castiel's almost transparent, black, wings have unfolded underneath them, passing through parts of the car like ghosts. Castiel blushes as he realises what has happened. This is the first time anyone has really seen his wings; and Dean seems absolutely astonished. Dean stretches out a weary hand, looking at Cas with an unasked question burning in his eyes. Castiel only smiles a little and closes his eyes, giving Dean the consent to touch this most private part of him. Dean touches first a finger, then two to the silky feathers of Castiel's wing. Dean feels Cas shudder beneath him, letting out a small moan of pleasure as he caresses his wings.
Starting to grind their hips together, Cas' eyes fly open; moaning at the sensations only Dean can give to him. Unable to stand it any longer, Cas reaches for the buttons of Dean's jeans. Dean stops him just as he pops the first button. Looking deep into Castiel's eyes Dean has one question. "Are you sure?" He asks in a strained, hushed voice.
"Yes." Is Cas' simple, husky answer as he moves to unzip Dean's pants, sliding them off before undoing his own belt and taking off his own pants.
Now, lying in the back of the Impala, in only their underwear, with Dean straddling Castiel, they start to move their hips against one another's again. Dean reaches out and gently touches the bones of Castiel's wing, slowly trailing his fingers down the feathers as Cas lets out a guttural moan, making Dean's arousal harden even more. Dean links a single finger into each side of the waistband of Castiel's boxer-briefs and slowly slides them down, letting his erection spring free. Pulling off his own boxers, Dean kneels between Castiel's now open legs, positioning himself. Looking up at Cas one more time, asking for consent, Dean thrusts into Castiel and stills, letting him get used to Dean's immense size. Dean kisses down Cas' chest as he starts to move inside of him, their mingled breathing, panting and moaning fogging up the windows of the old '67 Impala.