"D-d-dean!" Cas cried out, nails digging into the desk he was resting against. Dean was on his knees in front of him, Cas' cock deep in his throat. Dean was making small noises, humming around his lover's hard cock. He looked up at him, his green eyes meeting bright blue eyes that were filled with lust, dilated largely. Dean swallowed, the motion causing Cas' cock to pulse in his mouth. Dean reached around, slipping a slick finger into Cas' tight hole, rubbing him in just the right spots to make him buck his hips.
Cas couldn't do anything but cry out in pleasure, his hips bucking so hard into Cas' mouth he thought he would explode from the tightness he found in that action. He felt Dean's finger inside him, then there was another. His skin was on fire. "Dea- Oh fuckin-" He gasped, reaching a holding Dean's head still as he thrusted into his mouth over and over. He felt a third finger inside him, hitting his G-Spot perfectly. He thrusted with the rhythm of Dean's fingers, pulling back out of his mouth as Dean thrusted his fingers inside of him. With a strangled cry, Cas burst inside of Dean's mouth.
Dean moaned, swallowing down every last drop of his lover's seed. He loved watching Cas come undone. It was the most beautiful thing he had ever saw. He pulled off of his cock, the satisfyingly loud wet pop made his cock harder. He turned Cas around, not giving him a chance to recover from his orgasm, holding him down against the desk. "You're such a good teacher Cas. You and your amazing cock." He whispered as he undone his pants, letting them hit the floor. He quickly stroked his cock with his lubed fingers before lining up with him and pushing in slowly.
Cas' back arched, his cock pressed against his stomach as he dug his nails into the dark oak desk. He bit his lip, holding back the moan that so desperately wanted to escape his full pink lips. "D-Dean p-pleasee fuck me." He pleaded, cock already hardening again.
Dean did has he was told. He pushed in and pulled out, his pace slow at first. He grabbed onto his hips, pace increasing. He remembered the teasing Cas had done all through the class and it both pissed him off and turned him on. He didn't even notice that he had sped up, fucking into him relentlessly. He heard his lover's whimpers and moaned. "Fucking so good." He moaned, letting his eyes close. His nails dug into Cas' hips, bruises forming beneath his touch. He continued to pound into him, not giving in. He felt the threat of his orgasm and reached around, stroking Cas' cock fast and hard. He felt Cas come first, felt the tightening pressure of his clenched ass as he spilled his delicious come all over the desk. It sent Dean over the edge and his vision blurred, bright spots covering his view. He came down from the gloriously high a few moments later, cock softening inside of the older man. He pulled out, reaching for some tissues to clean them both up.
Castiel barely even noticed Dean helping him with his clothes. He was tired, extremely tired. He moaned softly, resting against Dean's bare chest. He felt Dean's heartbeat, steady and evened out now. He smiled into his soft skin, smelling the scent that was Dean. His Dean. He felt Dean's arms snake around his waist as he sunk into the warm welcome of sleep.