The brick of the alley wall was rough through the thin cotton of Dean's t-shirt, his jacket abandoned at his feet, and Cas's hands were warm, so warm as they pushed aside the cotton to palm Dean's hips, fingertips inscribing tiny circles into his skin. Castiel's mouth was hot and wet as he sucked at the base of Dean's throat, and Dean made sounds he'd never admit to when Castiel undid Dean's jeans and pressed a hand inside. Dean pushed his own hand hard against his mouth, eyes rolling back in his skull as he struggled for control, because it didn't matter how dark and late at night it was, how otherwise abandoned the alley seemed, they were in public, and anyone could hear.
Cas's teeth scraped lightly across Dean's throat before he pulled back, said, like he'd read Dean's mind, "You can be as loud as you wish, Dean. I've taken care of it." His hand had wrapped around Dean's dick, pulled a steady rhythm that served as punctuation to his words.
Dean swallowed hard and spread his legs at Castiel's gentle nudging, and Cas just dropped to his knees on the dirty pavement. He pulled Dean's jeans and boxers down to pool at Dean's feet, and his eyes were serious as he regarded Dean, like Castiel was weighing the options and choosing for them both. Castiel was on his knees, but Dean was under no illusion that he was the one holding the power here. Castiel traced the lines of Dean's dick with his tongue, then whispered Dean's name as a question against his wet skin.
Dean nodded, then cleared his throat and tried, in a voice gone hoarse, mouth dry and lips unsteady, "Yeah, I'm good."
Castiel didn't talk much after that, putting that hot, wet mouth to an even better use than sucking at Dean's throat. Dean clutched at the brick, the edges digging into his hands as he dropped his head back against the wall, unable to watch the red shine of Castiel's lips closing around his dick and still maintain any semblance of control. Castiel's palms rested on Dean's thighs, his fingers reaching back to brush Dean's ass before digging in, keeping Dean in place, the best of prisons. Dean closed his eyes, the cold of the wall fading to insignificance in comparison to the warmth of Castiel's lips, his tongue, and Dean couldn't help a whimper of complaint when Castiel withdrew.
"Dean," Castiel said, his firm tone calling Dean to open his eyes and look at him. "You can't hurt me. You can touch as much you'd like."
To emphasize this, he grabbed Dean's left hand, soothing with a touch the pain where Dean had scraped the skin, and firmly brought it to rest at the side of his head. Castiel's hair was unexpectedly soft against Dean's palm, and he petted the strands uncertainly before curling it in his fingers. Castiel murmured something, some pleased sound, and returned to what he'd been doing.
A lone flickering streetlamp licked a pale orange along the length of Castiel's trench coat, the profile of his face, appearing and disappearing like waves crashing and receding. A dumpster stood at Dean's left, a doorway to his right. The wall in front of him was also brick, blank but for a small red tag sprayed close to the dead end, the script so rushed it was difficult to tell if it was a gang sign, a sigil, or some kid pronouncing his current love for all to see. Dean thought he could just make out a + in it, or maybe it was a T. These were the details Dean tried to focus on instead of the warm velvet drag of Castiel's tongue, the vibrations that seemed to reach all the way into his gut as Castiel hummed his pleasure, the obscene sounds Castiel made as he pulled back and then forward again. There was an oil slick three feet behind and to Castiel's right, all darks interspersed with winding rainbow colors, and Dean tried to concentrate on this instead of the flash of blue and black as Castiel looked up at him, irises blown and eyes wide. The air was cool against Dean's exposed legs and arms, and it was impossible to concentrate on this when Castiel's mouth was so fucking warm, welcoming him in.
Dean had to wonder what kind of angel thought it was cool, anything approaching normal, to give his charge a blow job in an alleyway when with a press of his fingers, he could transport them to a hotel room, to a distant beach, an abandoned field or barn, anywhere that held even a hint of privacy instead of against a rough alley wall where anyone could walk by. Dean had to wonder what kind of angel was fine with said charge pulling his hair and shoving his dick down his throat.
(Answer: a really fucking awesome one.)
Then Castiel did something amazing and unexpected with his tongue, and Dean found it difficult to think at all.
"Cas," Dean gasped out, the sound a shard of pain pulled deep from his throat. Without meaning to, his other hand had wandered down to cup the back of Castiel's head; his fingers had tangled in the soft expanse of Castiel's hair. The only thing keeping Dean from thrusting with abandon was Castiel's implacable grip, pinning Dean's hips in place.
This time when Castiel stopped, he looked utterly wrecked. His chapped lips were red and swollen, his hair stuck out in a thousand directions from Dean's helpless tugs and pulls, and he looked utterly debauched, used. His eyes were altogether too keen, too knowing, as he asked, "Do you trust me?"
God help him, Dean did, and though he couldn't bring himself to say the words aloud, Castiel's eyes softened. When he leaned forward this time, he released Dean's hips, blood flowing suddenly back in under the skin; when Castiel pressed his hands to Dean again, it was to curl them against the cheeks of Dean's ass. Dean finally took the hint and let go. Castiel took him apart second by second, ripped pleasure from what seemed like his every nerve, and Dean was helpless to enjoy the ride.
Dean came back to himself slowly. First, he was aware of the slow drag of Castiel's tongue against his jaw; next, Castiel's hands rubbing light circles in his shoulders. Dean had slid down the wall at some point, but Castiel had pulled Dean against him, into his lap, so that instead of rough concrete, Dean felt the smooth fabric of Castiel's dress pants pressed against Dean's own bare thighs. His breath was still hitched, like he'd forgotten how to follow a measured pace in the wild, unsteady rush of orgasm. When Dean turned his head to face Castiel, Castiel slid his tongue between his lips and pressed a reassuring rhythm into his mouth, like Castiel planned to reteach Dean order by touch alone. Dean reached for Castiel's belt with the thought to undo that stability, but Castiel caught his hand.
"Dean," Castiel said, and Dean was gratified to hear the slightest pause before Castiel continued, "Let's go inside."
Dean considered a moment. "And if I said no?"
Castiel sat back the tiniest bit, took an audible breath. Dean waited. His hands absolutely were not shaking; and even if they were, he was still experiencing the aftershocks of adrenaline.
"I'd have to leave," Castiel said, and for a brief moment Dean felt the weight of every previous touch as a stone upon his chest, "to retrieve blankets and proper lubricant."
"Oh," Dean said. He pressed his hand to Castiel's cheek, said, "If it's all the same, wall sex is awesome, but—I'd prefer the bed."
"I thought that might be the case," Castiel said, eyes gentle, almost smiling, before he pulled Dean into another kiss.