Castiel wasn't entirely sure who had initially suggested the cloth and the ropes, but he knew exactly what he would say when he was kneeling on the bed and his wrists had been bound behind his back and his clothes taken off and Dean's hands on the cloth looked warm and sweaty and tentative and his perfect lips trembled with a question thrice repeated.
"Are you sure this is okay?" Dean asked, his voice rough and slightly anxious as he folded the makeshift blindfold into shape with fingers that shook a little – from nervousness or arousal or some strange mixture of both, Castiel couldn't tell.
"Yes," he replied, and it was honest – it was more than okay, and he felt his heart beat slightly faster when Dean slipped the material over his eyes and tied it around the back, his lips pressing a gentle kiss to his cheek as he did so. Being with Dean in this way, feeling the blood coursing slightly hotter and lower through his veins and burning pleasantly wherever Dean's exposed skin touched his and becoming temporarily free of the sense of sight for him, made him feel like both less and more than a broken angel in a human vessel. He was human, and he was Dean's, and he wasn't going to fight it away any longer. If he was going to be honest with himself, he'd never really wanted to in the first place.
So he allowed Dean to wrap his arms around him, all heat and skin and tentative hands, and when Dean's lips met his he kissed him back with the same quiet but building force, keeping his hips a careful distance from Dean's, feeling his body begin to react to the sparking friction between them and simultaneously dreading and craving the moment when their hips came together and lightning would jolt through them both. His arms ached to be around Dean, and he allowed the desire to begin to consume him, kissing Dean harder, biting his lip gently and coaxing a quiet groan from deep in his throat. He shivered as Dean's hands slid up his back, stroking his spine and pressing Castiel to him, closing the distance and almost hesitantly grinding against his hips, pushing against him, pulling a gasp from his lips and making his hands in their binds twitch with pleasure. He felt a desperate longing to break free of his bonds using his angel mojo and slide his hands over Dean's hips and onto his buttocks and push him closer, guide his steadily moving hips closer to him, but it would be unfair and he was enjoying the ache too much to break it.
Dean's movements were becoming stronger now, his lips moving from Castiel's mouth down to trace his jaw and brush against his neck, then harder, then the scrape of teeth and hands sliding to Castiel's shoulders and holding him tight as he gasped for air.
"Dean," he breathed, arching his back as Dean rolled his hips into him, his cock pressed against Castiel's stomach, pre-come dribbling out and leaving a dimly glistening stain on his skin. Dean growled into his skin, slipping one strong hand down Castiel's back and around to slide up his thigh and stroke him up the length of his cock, his fingers leaving trails of fire behind them. Cas moaned softly as Dean took both of their members in his wide, rough hand and guided his own hips against Castiel's, the quick and almost frantic movements of his hand causing the friction between them to intensify by what felt like a hundred degrees. Castiel could feel Dean's breathing becoming more rapid, and his own heart was beginning to beat faster as that odd but intensely pleasurable sensation began to seep through his burning veins and ignite his tightening skin, and the blindness – the senselessness – of it only intensified the feeling. His hands tightened into fists and he drew in a shuddering breath as Dean's free hand dug into the skin of his back and he came, his hips thrusting and pushing into Castiel's and forcing that tight heat against him and he could feel his entire body tensing and suddenly there was nothing, nothing at all but Dean's body against his and the almost violent shuddering of his climax ripping through his entire body, reverberating into his wings and echoed in Dean's lips still pressed against the skin of his neck, and then it was over and all that was left was haggard breathing and bare skin and the feeling of warm, sticky mess that wasn't entirely uncomfortable at all.
He blinked slowly as Dean slipped the blindfold off him, and when he saw Dean's face – the raw emotion, the brightly shining happiness and the pure love – he couldn't help but allow a quiet smile to spread across his face in the afterglow. It wasn't the kind of angelic glow that Castiel was used to. It was entirely blind, entirely senseless, entirely human, and entirely Dean's, and in this moment, that was all the fallen angel needed to know that he was still here.