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In this Cybertron, the planet thrived under a single banner, the Council of Primes and the Dragon Conclave, an ancient alliance between the thirteen bloodlines and the Predacon royal houses. Optimus Prime, youngest of the Prime lineage, had been bonded to Predaking, Crown Prince of the Dragon Conclave, in a political union meant to cement peace between grounders and fliers, mech and beast.
Five years later, the marriage was no longer political.
The royal citadel in Tyger Pax rose in tiers of black glass and living flame, its highest spire open to the night sky so the twin moons could bathe the Dragon Conclave’s throne room in silver. Down three levels, in the private wing reserved for the bonded pair, the solvent chamber was carved from a single slab of obsidian veined with molten gold. Heated solvent fell from the ceiling in a constant, steaming curtain, scented with ember-root and star-anise (Predaking’s favorite).
Optimus had been away for nine days this time, not on war or diplomacy, but on a simple inspection tour of the southern forges. Nine days of watching Predaking’s heat cycle crest without him. Nine days of receiving increasingly desperate holo-messages that ended with the Predacon king on his knees, wings trembling, begging his Prime to come home and breed him until his valve couldn't take anymore.
Days of Optimus excusing himself to the refresher every few hours just to palm his spike and imagine burying it in that ruined, waiting heat.
Optimus had broken every speed law between the forges and Tyger Pax.
He found Predaking exactly where he expected: standing beneath the solvent fall, wings half-spread to catch the heat, tail lashing slow arcs through the steam. The Predacon wore nothing but the ceremonial collar (black dragon-scale leather inlaid with rubies, the royal crest of their union engraved on the ring). Solvent sluiced down the powerful curve of his back, tracing every ridge of spinal strut before cascading over the swell of his aft and dripping from the plush lips of his valve.
The moment Optimus stepped into the chamber, Predaking’s head snapped around. Golden optics flared bright as twin suns.
“Optimus—” The name fractured into a snarl as Optimus kicked his mate’s legs apart. Hot solvent rained down on them both, turning the air thick and white with steam.
The Prime didn’t speak. He crossed the distance in three strides, armor half-shed already, and slammed Predaking chest-first against the obsidian tile. One hand fisted in the collar’s ring; the other pinned a wing at the joint. The impact rattled the wall and sent solvent spraying in every direction.
Predaking’s claws scrabbled for purchase, breasts crushed to the warm stone, nozzles sore and the solvent and ran in rivulets down his belly. His tail coiled instinctively around Optimus’s thigh, urging him closer.
“What brought this on?” Predaking rasped, voice rough with need and laughter. His breasts were crushed to the tile, nozzles scraping deliciously with every heave of his chassis. He tried to push back, but Optimus’s held him pinned.
His vents fogged the glass panel beside them in frantic bursts. “I expected at least a greeting, my Prime—”
“You,” Optimus growled against the base of his neck, teeth scraping the sensitive cabling there. “Nine days of messages. Nine days of you on your knees in the lubricant, dripping down your thighs. You think I could wait another nanoklik?”
He dragged his spike, already unsheathed, flushed dark blue and dripping, between Predaking’s thighs. The head nudged swollen valve lips, just sliding the monstrous length through slick folds without entering, grinding over the fat pearl of his anterior node. Predaking’s entire frame jolted as his knees bucked. A sharp cry tore from his throat as his valve spasmed, squirting a hot gush of lubricant that splashed against Optimus’s plating and ran down both their legs.
“Already?” Optimus rumbled, dark and delighted. He thrust again, slow and filthy, letting the ridges of his spike drag through that soaked valley. “Just from this? I haven’t even breached you—”
“Been pent up,” Predaking mumbled, face pressed to the glass, vents fogging it in frantic bursts. His tail tightened around Optimus’s thigh, wings trembling. “Nine days of heat cycle—nine days of court functions with stuffy nobles, no way to release—nine days of dreaming about this exact moment—”
Optimus didn’t let him finish, obliging.
One brutal thrust and he was inside.
Predaking screamed. His valve swallowed Optimus to the hilt in a single stroke (calipers rippling, forge entrance kissing the head like it had been starving). The bulge in his abdomen was obscene, visible even through the steam, distorting the plating as Optimus’s spike rearranged his internals. Solvent sluiced over it, tracing the outline of the intrusion before dripping off Predaking’s thighs.
“Still so tight,” Optimus snarled, hips snapping forward hard enough to crack the obsidian. He held Predaking by the collar and one wing, fragging him with the kind of force usually reserved for battle. “Even after you spent nine days stretching yourself on every toy in the palace—still so fragging tight for your Prime.”
Predaking could only whimper, overload already coiling low and vicious. His breasts dragged against the wall with every thrust, nozzles sore. His valve made filthy, wet sounds, overfull, oversensitive, clenching greedily around the spike that finally filled him right.
“Look at you,” Optimus breathed, slowing just enough to grind deep, rolling his hips so the head kissed Predaking’s forge entrance. “Squirting the moment I touch you. Leaking from every hole. I bet the entire court knows their crown prince is a desperate slut for his Prime’s spike.”
He reached around, cupping one heavy breast and squeezing until Predaking couldn't hold back his noises. His thumb rolled the nozzle mercilessly, timing each pinch with a brutal thrust that punched the air from Predaking’s vents.
“Tell me,” Optimus demanded, voice ragged. “Tell me who you belong to.”
“You—” Predaking sobbed, wings shuddering, tail lashing hard enough to slap the tiles. “Only you—always you—please—”
Optimus spun him suddenly, pressing Predaking’s back to the tile instead. The new angle let him watch every expression, optics blown wide, mouth open on silent screams, breasts bouncing with every thrust. Solvent poured over them both, turning Optimus’s red and blue plating slick and gleaming. He hooked Predaking’s thighs over his forearms, spreading him wide, and slammed home again.
The bulge shifted with every stroke, obscene and perfect. Predaking’s valve fluttered wildly, squirting again on a particularly deep thrust that nudged his forge open just enough to make him see stars.
“Gonna knot you,” Optimus promised, voice fracturing into a growl. “Gonna lock inside and flood you—fill this royal valve until you’re dripping down the throne room steps tomorrow—until every lord smells their crown prince claimed and bred.”
“Yes—yes—Optimus—!”
The knot swelled. Caught. Locked.
Predaking overloaded with a roar that shook the obsidian walls, valve clamping down so hard Optimus saw static. Energon fountained from his nozzles in powerful arcs, painting Optimus’s chest and face. His node pulsed visibly, calipers milking the knot in desperate waves as transfluid jetted deep into his forge.
Optimus followed with a guttural snarl, grinding as deep as possible while his spike pulsed and flooded. The sheer volume forced some back out around the knot, mixing with Predaking’s lubricant and running down Predakings thighs in thick, creamy streams.
The knot held them together for long, trembling kliks, solvent drumming over their joined frames like a heartbeat. Optimus felt every pulse of Predaking’s valve milking him, every flutter of inner calipers trying to drag him deeper even though there was nowhere left to go. The steam curled around them, thick and fragrant, carrying the mingled scent of ember-root and spent transfluid.
They stayed locked together under the solvent fall, trembling, venting in harsh bursts. Optimus gently lowered Predaking’s legs but didn’t pull out. Instead he cupped his mate’s face, thumbs brushing away solvent and tears.
“Missed you,” he whispered, pressing their foreheads together.
Predaking laughed, shaky and wrecked. “Next time you leave for nine days, I’m chaining you to the throne. The forges can inspect themselves. Either that or I’m coming with you. Diplomacy be damned.”
Optimus kissed him slow and deep, knot still pulsing gently inside.
“Deal,” he murmured. “But first… round two. I still owe you for every message you sent.”
Predaking’s valve clenched around the knot in eager agreement.
Optimus answered by rolling his hips, slow and deliberate. The knot tugged at Predaking’s rim, stretching him wider, forcing a broken moan from the Predacon’s throat. Solvent sluiced over the obscene bulge in Predaking’s belly, tracing the shape of Optimus’s spike locked inside.
“Still so greedy,” Optimus murmured, lips brushing the corner of Predaking’s mouth. “Even knotted full, you want more.”
Predaking’s wings shivered, spreading wide against the obsidian. “Always more,” he growled. “You left me empty for nine days. Nine. I deserve to be ruined twice for every day you were gone.”
Optimus laughed, low and dark, and shifted his grip. One arm hooked beneath Predaking’s thighs, the other still fisted in the collar. With a flex of hydraulics he lifted the Predacon clear off the floor, knot never slipping, and turned them both so Predaking’s back pressed to the warm glass wall instead of tile. The new angle let gravity drag Predaking down harder onto the knot, forcing a sharp cry from his vocalizer.
“Count them,” Optimus ordered, voice rough. “Eighteen overloads. One for every day I was gone, doubled for interest.”
Predaking’s optics flared gold. “Start now.”
Optimus did.
He started slow, grinding in tiny circles that dragged the knot against Predaking’s over-sensitized rim. Every shift sent sparks shooting up the Predacon’s spinal strut; his tail lashed, coiling tight around Optimus’s waist to anchor himself. Solvent poured over them in sheets, turning every slide of plating into liquid friction.
Then Optimus pulled back—just enough for the knot to tug free with a wet pop that made Predaking sob—and slammed home again.
Sensitive from the earlier fragging and knotting, he was much more easily teased. The second thrust punched the air from Predaking’s vents. His valve clenched hard, squirting another gush of lubricant that splashed against Optimus’s abdomen and ran pink down the Prime’s legs. The bulge reappeared instantly, larger this time, knot already swelling again.
“One,” Optimus growled.
He set a brutal pace—no warm-up, no mercy. The glass behind Predaking squealed with every impact, fogging and clearing in frantic bursts as the Predacon’s vents blasted hot air across it. Predaking’s breasts bounced wildly, nozzles leaking in steady streams that painted Optimus’s chest and dripped from his chin. Each thrust forced another spurt, until the solvent ran pale pink around their pedes.
Predaking’s claws dug into Optimus’s shoulders, leaving deep scratches in the red plating. “Harder,” he snarled, fangs bared. “I’m not made of glass—”
Optimus obliged. He spun them again, pressing Predaking face-first to the glass this time, wings pinned flat by one massive hand between the joints. The Predacon’s breasts squashed against the fogged surface, nozzles dragging with every thrust. Optimus reached around and pinched both nozzles at once, twisting viciously.
Predaking screamed. His valve spasmed, squirting again—so much the solvent couldn’t wash it away fast enough. The puddle beneath them grew thick and slick.
“Two,” Optimus counted, voice steady even as his own overload coiled hot and low.
He didn’t stop. Couldn’t. Each thrust drove Predaking higher up the glass until his pedes left the floor entirely, held aloft by spike and brute strength alone. The knot swelled larger, catching earlier, locking them together again on the eighth thrust.
Predaking overloaded a third time the instant the knot seated, entire frame seizing, wings snapping wide.
Optimus snarled, grinding deep, flooding Predaking’s forge a second time. The overflow gushed out around the knot in thick pulses, running down Predaking’s thighs in creamy rivulets that the solvent couldn’t dilute.
They stayed locked like that, trembling, venting in harsh bursts. Predaking’s valve fluttered endlessly around the knot, milking every last drop.
“Three,” he whimpered, voice wrecked. “Only fifteen more to go.”
Optimus laughed breathlessly against the back of his neck. “We have all night, my king.”
He carried Predaking out of the broken shower still knotted, solvent still pouring over them both, and laid him on the wide obsidian ledge that served as a bench. The knot held on for quite a while—long enough for Optimus to tease Predaking’s breasts, to suck bruises into the soft plating of his throat, to whisper filth and praise in equal measure.
When it finally eased, Optimus didn’t pull out. He simply flipped Predaking onto his back, hooked those powerful thighs over his shoulders, and started again.
By the time the solvent began to cool, Predaking had lost count somewhere around twelve. His voice was gone, reduced to static and broken whimpers. His valve was a swollen, gaping mess—valve lips and anterior node puffy and used, inner folds fluttering visibly every time Optimus pulled out just to watch them try to close. Lubricant and trans fluid leaked from his valve in steady streams, pooling beneath.
Optimus knelt between his spread thighs, spike still hard, still dripping. He pressed two fingers alongside his length, stretching Predaking wider, watching the Predacon’s back arch off the ledge.
“Still not enough?” he teased, voice gentle now.
Predaking could only shake his head, optics blown wide and glowing. His tail coiled weakly around Optimus’s wrist, urging him deeper.
The Predacon was a wreck, valve gaping and twitching, breasts bruised and leaking, tail coiled weakly around Optimus’s wrist.
Optimus leaned down, kissed him slow and filthy, and slid home again. The prime was still hard, still buried deep, still fragging him slow and steady like he’d never stop.
Outside the broken solvent chamber, the twin moons climbed higher over Tyger Pax, bathing the citadel in silver light. Inside, the Prime and his dragon king burned through the night—eighteen overloads, twenty, thirty—until the only sounds left were the wet slap of plating on plating and the endless, reverent chant of each other’s names—the citadel would probably awaken to the sound of their crown prince screaming his Prime’s name for the hundredth time.
Peace, in their world, had never sounded so perfectly wrecked.