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It'd been days, days on end of losing his mind in a hotel, eating room service and delivery pizza, watching TV, cleaning his guns, bathing and brushing his teeth and pissing and shitting, all under Castiel's watchful eye. Days since he'd been told I cannot let you leave this room, or my sight, until Sam returns--Lilith's minions are too strong in this town, and she will use you as bait in this battle if she may, but I can watch you, and keep you safe. Days of pacing, screaming frustration inside, and worry, and numbness, and terror. Days of knowing his brother was fighting in a war for their lives while he was trapped, a prisoner in a room with tacky paintings and a pink-and-grey bedspread and an angel who lurked just out of eyesight no matter where he looked.
Days of bouts of restlessness and boredom and loneliness and horniness, itching up under his skin, and of trying to hide himself from the angel, knowing uncomfortably that it was probably futile. That Castiel probably now knew him better than anyone in the world, save Sam.
That was...a little sad, maybe, he realised, that only one person in his adult life that he wasn't related to had ever had the chance to observe him unflinchingly, to see him as someone who didn't flit in and out of their life on the breeze. It made him feel even lonelier.
It wasn't surprising, then, when he woke up one night to piss, half-dead on his feet with exhaustion, and found himself standing in front of the mirror, watching his hand slowly stroke his cock to hardness while the faucet ran. It had been days and days since he had done this, too, uncomfortable in the absence of privacy, but now he just couldn't bring himself to care. He watched himself, his face, circles under his eyes and course stubble on his chin. His cock leaked a drop of clear fluid as he looked, not even feeling what he was doing to his body until Castiel spoke.
"Dean. Are you well?"
"No," he whispered.
The angel stayed silent, eyes calm in the mirror, not accusing but not looking away, either. He stood still, leaning in the bathroom doorway, and there was nothing in his eyes but the sickly yellow shine of the light Dean stood under.
"I'm not going to stop, if that's what you were hoping," Dean said.
"Why do you do this to yourself?" Castiel asked.
Dean sighed, squeezing the head of his cock viciously, watching his hand as it smeared slick all over himself. "Because I need to."
"You aren't enjoying yourself," Castiel said, and there was something almost like compassion in his face then, just for a moment, before his features smoothed back into impassiveness.
"Doesn't matter," Dean said. "Do you ever touch yourself, in that body?"
A slow, reflected blink. "I do not. I have more pressing concerns."
"What do you think would happen if you did?"
"It is not for me to contemplate."
Dean laughed, low under his breath, a sound like he'd been punched. "Are you going to keep contemplating me?"
"You know I can't let you out of my sight, Dean."
"Yeah, I know." Dean nodded, looking into his own face, seeing a shimmer of sweat gathered on the edge of his upper lip. His tongue darted up to lap at it, eyes closing for a second, opening again as he pulled harder at his cock. His heartbeat was kicking up in speed. "You watched me sleep, before. Before this."
"Yes."
"Why do you watch me? Do you get off on it or something?"
"It's my job to watch you."
Dean laughed again, lifting the hand braced on the counter to clench into his shoulder, fingers digging into the corded muscle there. "Are all angels so hands-on in their work?"
Castiel was silent.
"Uriel said you liked me. What did he mean by that?"
"It is also my job to keep you safe, Dean. I feel that this is a goal easier achieved if I have a...personal stake in the matter, I suppose."
"Bullshit."
"Excuse me?"
"You don't just make yourself care about someone because you think you're supposed to, it doesn't work like that." Dean's hand stilled, holding himself, as he turned his face from the mirror to look Castiel in the eye. "I saw you looking when I kissed Anna in that barn, and I know you felt something, I saw it in your face. You're not as heartless as you let on. What did you feel, when you watched us?"
"Dean--"
Dean swiped a thumb up the underside of his cock, and he could feel it this time, rushing low in his belly. A surprised burst of air pressed its way out between his lips--he could feel the warmth of the room, the shiver of his fingers across his nipple, gone tight and hard under his hand. His other hand sped up, hips starting to work into his grip.
"Are you going to watch me come?"
There was something almost rough, now, in Castiel's voice as he spoke, a tightness around his eyes as Dean turned back to watch him in the mirror. "I don't have a choice."
"You could close your eyes," Dean said, closing his own, biting his lip. He looked up again to see Castiel nod.
"I could."
"But you won't."
He could feel it gathering, muscles tensing and twitching under his hand as he ran it over his belly, his chest, up and down his upper arm as he worked himself furiously. Down to his balls, cupping them in his hand, and his eyes jerked up to meet Castiel's as it hit, breath stuttering out of him as he spurted into his waiting hand. He leaned in, pressing his face to the mirror for a moment, letting himself come down before straightening again.
Castiel stayed still, back pressed to the edge of the open door, as Dean came towards him. Still wearing that stupid coat, still staring--but not quite calm, maybe. Dean had himself half-convinced of something there, some faint grey haze clouding his eyes, some tense cast to his face.
Dean watched him as he stood before him, naked in front of his clothed body, in the seedy half-light. Watched as he raised a hand, smearing a wet rope of semen across the angel's lips, soft beneath his rough fingers. He watched as Castiel took a breath, the faintest hint of a quiver there, before darting his tongue out across his shining, dirtied mouth.
"That's what I thought," Dean said, stalking back into the bedroom.