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Prowl had spent his entire functional life believing he was devoid of anything resembling a "sex drive." He operated under the firm conviction that his processor was far too evolved, too optimized for logic and tactics, to ever be swayed by the base, primal urges of the frame.
Yet, here he was. In the sterile confines of his private washroom, Prowl was stroking his spike, his thoughts consumed entirely by Optimus Prime.
He had made a habit of this in the washroom. Partly because he loathed the idea of his quarters being defiled, but mostly because the direct comm-link to Optimus remained active at all times for emergencies. The mere thought of accidentally vocalizing the Prime’s name while servicing himself, only to have Optimus rush to his room in a panic, was a catastrophe Prowl refused to risk. But as the Prime’s Second-in-Command, he couldn't simply sever the link. Optimus, for his part, seemed blissfully unaware of Prowl’s inner turmoil, occasionally leaving his own end of the comm-link open with a thoughtlessness that bordered on agonizing.
Despite his commander's apparent obliviousness, Prowl could not relinquish his hunger. Who wouldn't desire Optimus Prime? To behold his touch, his voice, his very form was to invite a certain kind of worship. It wasn't uncommon for Cybertronians to feel affection or even lust for one another, but the object of Prowl’s fixation was the Prime—the most hallowed and precious being on Cybertron. Chosen by Primus, his commander, the very spark he had sworn his life to protect.
And yet, the memory of Optimus’s transparent chest-plates, radiating that pure, ethereal light, haunted him. The way his plush lip-plates were revealed whenever he deigned to retract his battle mask played on a loop in Prowl’s mind.
He couldn't escape the moments when those blue optics dwelled on him with such kindness. He fantasized about those large, capable hands wrapping around his spike, about that stoic, noble face finally breaking into a mess of pleasure. But in his mind’s eye, Optimus remained immovable—stern, regal, and composed. He imagined the Prime either comforting him with a perfect, unwavering expression or rejecting him with a cold, definitive authority.
Ultimately, it didn't matter. The mere image of that face was enough to transmute Prowl’s logic and reason into a desperate, bottomless yearning.
With a sharp intake of air, Prowl recalled the sound of Optimus calling his name and finally vented his transfluid. As the heat began to drain from his frame, he triggered the oil shower, meticulously scrubbing away any trace of his self-indulgence. He furrowed his brow; the cloying, sweet scent of transfluid seemed to cling to his fingers. Optimus might be dense regarding social cues, but Prowl refused to leave any scent-marker that might hint at the "impure" thoughts he harbored in the Prime’s presence.
He reached for a specific oil, a common scent, though now increasingly rare. It was a fragrance Orion Pax had once mentioned liking, back when they were both merely officers of the law. With the journey to Earth, a planet of organics, looming ahead, such luxuries would soon be impossible to find.
Clean, composed, and appearing as though he hadn't just committed an act of private sacrilege, Prowl made his way toward Optimus’s office. Yet, every optic that met his felt like a needle. He felt as though the entire crew knew exactly what he had done while thinking of their holy leader. The paranoia only intensified when he entered the Prime’s quarters.
Optimus looked up, his optics widening slightly. Does he know? Prowl wondered, his spark stuttering.
"You smell pleasant, Prowl," Optimus remarked softly.
Ah, the oil. Prowl realized. He wore the same scent every day, yet Optimus commented on it every time. Was he truly that unobservant? Or was he simply that focused on Prowl’s presence?
"Have you reviewed the data I sent?" Prowl asked, his voice clipped.
"Mostly."
"Mostly? I gave you more than enough time. Why is it not finished?"
Prowl moved closer, his irritation masking his lingering arousal. As he leaned over to inspect the datapack, Optimus tilted his head toward him and suddenly retracted his battle mask. The Prime’s facial plates were running abnormally hot.
Is he ill? Is that why he’s behind schedule? Prowl opened his mouth to deliver a lecture on health maintenance, but stopped. Optimus was resilient; a lecture might only sour the mood. Instead, Prowl focused on the data, determined to be the most diligent, most useful bot the Prime had. He noticed the elevated temperature radiating from Optimus’s frame throughout their work, but as the Prime showed no other symptoms of malfunction, Prowl eventually pushed the concern aside.
The moment Prowl left for his own quarters, Optimus retreated to his berth. Pulling a thermal blanket over his lower half, he quietly cycled his valve open and began to stroke himself. The soft protoform of his external nodes was already swollen, and lubricant began to weep from the seam of his valve. Feeling the internal walls twitch with a phantom hunger, Optimus slid his fingers inside.
His other hand moved to his chest. He opened his plates, exposing the glowing blue crystal of the Matrix. He began to caress it, his twisted fantasies transforming his own fingers into Prowl’s pristine, white hands. Optimus let out a low moan, recalling the exact moment Prowl’s fingers had once brushed against the Matrix. His hips began to buck involuntarily.
Carrying the Matrix was a burden of constant, low-level pain, a sensation he had long since adapted to. But it was Prowl’s fault, in a way, that the pain had turned into something else.
It had happened during a repair session with Ratchet. They had run out of localized numbing agents, and Optimus had to endure the surgery while fully online. The Matrix had begun to thrum and pulse with his distress, and Prowl, thinking something was wrong with the relic, had reached out to steady it. The moment Prowl’s fingers made contact with the Matrix, a jolt of electricity had shot through Optimus—not of pain, but of a searing, terrifying pleasure that raced from his spark down to the very base of his valve.
The surgery had ended, and he had recovered, but the sensation remained burned into his memory. He had been unable to resist the curiosity. When he finally experimented, sliding a finger against the inner housing of the Matrix, his interface panels had snapped open instantly, slick with lubricant. He knew how profane it was, yet he couldn't stop. He had discovered what "pleasure overload" truly meant.
He hadn't been a particularly lustful bot before, but now, his valve ached incessantly. The ache worsened whenever Prowl was near. And that scent—that oil Prowl wore. It was common enough on Cybertron, but now, the mere whiff of it caused Optimus’s internal nodes to tighten with longing.
Optimus thrust his fingers deeper, imagining it was Prowl. He imagined Prowl’s clean, meticulous fingers being defiled by his own fluids. What did Prowl’s spike look like? Was it as elegant and precise as his personality? He craved the feeling of Prowl’s spike filling him, crushing the internal nodes his own fingers could never reach. He wanted to be ruined by him.
Heat flooded his systems. Optimus opened his mouth, his glossa lolling out as he panted, looking more like a beast in heat than a Prime. He focused on Prowl’s cold, beautiful optics, the way his hand felt when he briefly touched Optimus’s shoulder in the line of duty. With a choked cry, Optimus reached his climax.
He lay there shivering, wrapped in his blanket. The release brought temporary relief, but it was hollow. He wanted the real thing. He wanted Prowl’s transfluid to fill his gestation chamber until he was heavy with it. He reached back into his chest, circling his fingers around the Matrix, his frame still twitching with the aftershocks of his overload.
When he had complimented Prowl’s scent earlier, he had been terrified Prowl would see right through him. Or perhaps... he had hoped for it. But Prowl had simply been his usual, clinical self. And then he had leaned in so close...
The sight of Prowl working so diligently only made Optimus feel more wretched, more obsessed.
Just as the heat began to stir in his valve again, Optimus felt a sudden draft. He turned his head slowly, his optics widening in horror.
Prowl was standing in the open doorway, a canister of painkillers in his hand, his mouth agape.
"...I heard you calling my name... crying out..." Prowl stammered.
Prowl’s gaze dropped from the fingers inside Optimus’s chest to the slick, dripping valve between his legs. Optimus was too stunned to move, his optics landing on the emergency comm-link on his bedside table. It was active. He always remembered to turn it off before this—but today, he had been too far gone to remember.
"I... I..."
Prowl felt as though he had stepped into one of his own dreams. In all his fantasies, he had never imagined Optimus this broken, this unraveled. And yet, this reality was infinitely more seductive than the untouchable icon he had imagined. He wanted this version of Optimus more than anything in the universe.
His logical circuits were screaming, but the sight of Optimus looking like he was on the verge of tears shattered his restraint.
"Forgive me. I should have announced myself," Prowl said, moving toward the berth with predatory focus. "I thought you were in pain."
He reached out, his white hand sliding up the inside of Optimus’s thigh. Even a Prime was a creature of the forge, capable of desire. Optimus had been Orion Pax once; he hadn't changed into a god overnight. But even as Orion, Prowl had never imagined him like this—wanton, desperate, and wanting him.
As Prowl’s fingers brushed against his valve, Optimus felt his systems redline. Prowl noticed his shaking and gave his shoulder a firm, reassuring squeeze—the same way he did when Optimus performed well in a tactical briefing.
"Relax," Prowl whispered, his own voice thick with a hunger he could no longer hide.
Prowl slid a finger into the Prime’s drenched valve, testing the depth, while his other hand moved to Optimus’s lower abdomen.
"This should be sufficient," Prowl murmured.
Before Optimus could ask what he meant, Prowl’s spike deployed. It was already rigid, weeping transfluid at the tip. Prowl parted the Prime’s valve-lips and pressed his head against the entrance.
"Do you wish for me to proceed?" Prowl asked. He sounded as though he were asking for permission to file a report, but his heated facial plates told a different story.
Optimus hesitated, worried Prowl was only doing this out of a sense of duty. Seeing the silence, Prowl reached into Optimus’s chest, his fingers making contact with the Matrix.
"Does this please you? I will not enter unless you command it. I will simply continue to do... this."
Prowl’s fingers began to probe the housing of the Matrix. Optimus’s back arched, his intake hitching.
"P-Prowl!"
"Tell me, Prime. I cannot act without my god's permission."
There was a desperate edge to Prowl’s voice now. His spike was grinding against Optimus’s entrance, stretching the protoform.
"Grant me permission, Prime," Prowl hissed, leaning up to press a kiss to his jawline.
"...I want you," Optimus gasped, his optics dimming with pleasure.
"What do you want? Say it clearly."
"Frag me... please... now..."
Prowl didn't wait. He slammed into the Prime’s valve with a feral intensity. He felt the seal give way, but he didn't slow down. He knew Optimus’s frame could take it. With every thrust, Prowl’s fingers worked the Matrix, stimulating the internal nodes from both ends. As Prowl punched through the gestation seal, bottoming out in the chamber, Optimus let out a shattered cry, reaching for him. Prowl caught his hands, lacing their fingers together as he buried himself deep and filled the Prime with his heat.
In the aftermath, Prowl lingered, taking in the sight. Optimus lay there with his chest-plates wide open, his frame stained with pink fluids, his face a mess of lubricant and coolant tears. This was the real Optimus Prime.
"If you find yourself in such a state again, I expect you to call for me," Prowl said, leaning down to click the transparent chest-plates shut. He kissed the glass over the glowing spark. "Or would you prefer I find you? Like today?"
Optimus could only let out a faint, dazed moan in response.
Prowl cleaned the immediate area around the Prime's valve but purposely left the panel slightly ajar, with excess transfluid still leaking out. He pressed the panel shut firmly, causing the swollen valve protoform to pinch. Optimus moaned, a final jolt of pleasure racking his frame.
"I want you to carry my mark," Prowl whispered, kissing the Prime's helm. "I want you filled with me at all times. Do you want that too?"
Optimus gave a weak, tired nod. Satisfied, Prowl tucked the blanket around his commander and slipped out of the room, a rare, triumphant smirk on his face.
As he stepped into the corridor, he nearly ran into Jazz. Prowl immediately smoothed his expression.
"The Prime is unwell. He should not be disturbed for the rest of the shift," Prowl stated coolly.
"Ha! You finally did it! Congrats, buddy!" Jazz grinned, slapping Prowl on the back.
Prowl froze, his optics wide. Jazz just kept laughing, nudging him playfully.
"I’ve been watching you two 'interface' with your eyes for vorns. I was wondering when you'd finally get around to it! Maybe now you'll be less of a literal pain in the aft to work with."
Prowl stared, rendered utterly speechless. Jazz leaned in, his visor flashing mischievously as he whispered:
"Don't sweat it. I made sure the internal surveillance for this sector 'glitched' for the last hours. Enjoy the glow, Prowl."
With a wink, Jazz strolled past, leaving the tactician standing in the hallway, dumbfounded.