This is smut. The relevant warnings include: dom!Dean, sub!Cas, BDSM, top!Dean, bottom!Cas, sex machines, and sounding (if you don't know what that is, you might want to go look it up before you read). Just a word to the wise.


The machine pumped in and out of Cas at a moderate rate; fast enough to keep Cas squirming to close his ankles against the spreader bar locked wide, but not so fast that he'd come from taking the thick dildo up his ass alone. Dean hovered at Castiel's hip and watched him tilt his head back into the pillow and close his eyes, a shuddery sigh escaping past the ring gag holding his plush lips wide open. Watching his lover's face, he slowly pumped Cas' cock and licked his lips. While his own dick was screaming for attention, he could stave off his need with the knowledge of what was to come; the best part about setting a machine to fuck Cas was that it gave him two hands to pull Castiel apart, layer by layer.

With his free hand he reached for the syringe loaded with lubricant. Gently, he centered it tip to tip with Cas' erection and depressed the plunger with agonizing slowness. Cas thought so too and bucked, eyes shooting open to find Dean's as he moaned in strung-out ecstasy. His hands clenched in their cuffs at his sides almost convulsively as the machine's program slowed down but compensated by vibrating the dildo. Dean smirked and withdrew the nub of the syringe, putting it down and reaching for the real prize.

He breathed on the sound to warm it up (but not too much, because the shock of cool metal sinking into hot flesh was half the fun; he knew from personal experience). With as much delicacy as his lust-quivering hands could manage, Dean placed the round end of the probe to the dip in the swollen head of Cas' dick. He let the tip circle the hole slowly and was rewarded with a choked, involuntary grunt-whimper-exhale. Biting his own lip, Dean righted the sound so that it was parallel with Cas' cock and pushed it in ever so slightly.

The effect, however, was quite spectacular. As the rod leisurely parted flesh, Castiel began a litany of moans that only increased as Dean pressed forward. He could feel the narrow channel opening up, unfurling like a flower to allow the sound easier passage. About an inch and a half in, Cas began the choking noises, aborted little groans coming from deep within the bound man's throat without thought or command. Dean twirled the sound where it was, giving Cas a moment to breathe, and he looked up to the angel's face. There were tears running down his cheeks and he was sobbing breathily through the gag. Dean shifted the hand holding the shaft up, pinching the rod between his thumb and forefinger so that it wouldn't slide down further before Cas was ready. His other hand came up to cup Castiel's face, running a thumb across his wide, flat cheekbones. Cas' eyes fluttered open and Dean felt a jolt of arousal and love and adoration zing across the back of his neck, both trust and lust laid bare and vulnerable. He smiled warmly and brushed the hair from Cas' sweaty brow, leaning in to press a lingering, chaste kiss to his lower lip.

"You are perfect."

That was all he had to say; it encompassed everything. Cas' eyes closed at this benediction, soulfully and with the weight of his whole being, and Dean removed his hand with one last caress.

Pushing the palm of his hand into his own throbbing crotch one last time, Dean held Casitel's pulsing cock in one hand and the sound in the fingers of the other. Unhurried, he sunk the probe fractions of inches into Cas' cock, slow but unstopping. He straightened Cas' penis. With a convulsion the member opened up fully and allowed the sound to slide down with the help of gravity and it bottomed out. A guttural, animalistic sound clawed its way from Cas' chest and everything froze; the only sound was the mechanical whirring of the vibrator still spearing Cas' ass as it moved in and out of him gently. The sphere on the end of the sound nestled into the valley of the rim of his hole, all six and a half inches of metal encased in the smallest of passages.

Whispering soft encouragements and mindless sibilance, Dean plucked at the ball, twisting it and churning the rod stiff inside Cas' dick. Lazily, he slid the sound out a few inches then let it go and watched it hilt itself again. Castiel's whole body shuddered. A wicked grin broke out across Dean's face as he fingered the sound. Now it was time to play.

With a gentle parting flick to the tip of the sound, he let go of the rod and felt for the control to the machine. Dean sucked in a shaky, lustful breath and toggled the setting up. The vibration continued to hum through Cas' ass – Dean could feel it buzzing, making Cas' skin electric to the touch – but the pace and depth of the thrusts grew. Cas vocal cords had a mind of their own. They screamed their pleasure and pain as loudly as the ring gag would allow and hiccupped in time with the machine's plunges.

Dean drew on Cas' cock with deliberate, firm pulls. He shuffled his knees back so he could easily bend over and held Cas out so he could lick straight up the straining line of flesh and blood. He cupped Cas' balls and rolled them while his lips found the head, leaking precome around the metal ball. Placing the hand not playing with testicles on Cas' chest to ground him, Dean began to suck.

Cas began chanting his name – gruff, muffled, and forced from his lungs with each push of the machine. Dean increased his suction more and more, until, slowly, the rod began to rise from its resting place. Like drinking milk from a straw. He stopped sucking and let the probe fall back into place, repeated the procedure four times. The fifth time, the sound clacked against his teeth and he lightly closed them around it, lifting his head, pulling the sound with him. Carefully, he slid it out most of the way, about five inches, and then brought his head back down. Effectively, he was fucking Cas' cock with his mouth.

One particularly loud and stifled "DEAN" made him grin and lose his grip. He watched the rod slide home again and his lips descended to the head one more time. He bit the rod gingerly with his front teeth, wrapped his lips around the crown of Cas' cock, and hummed.

The bound man's eyes slammed shut. Castiel flew to pieces, thrashing in what little wiggle room he had. Come gushed up around the sound and over the tip, rolling past Dean's lips to run down the length. Dean continued humming until Cas' hips quaked and pained sobs fell from the open gag. He flipped the switch to the machine off and it retracted, still lightly vibrating as the dildo glided free. Dean gently disengaged and slipped the sound out of the wilting erection with care, softly lapping up Cas' release.

Cas let out a whimper as Dean pulled the ring from behind his teeth and ran his hands over all the skin he could touch. Fingers eased their way to the cuffs binding Cas' ankles and wrists and undid them, rubbing life back into the flesh. Cas' eyes remained closed but there was a certain peace about him. Dean kissed up Cas' chest and draped himself over his lover. He nestled his face under Cas' jaw, kissing, murmuring love and adoration, hands still roaming, smoothing, and soothing. When Dean felt a light arm across his back, he knew Castiel had come back to him and settled down for a respite before it was his own turn.