Chapter Text
When the Primes had locked Sentinel up in the dark empty cell below the tower they hadn't merely locked him a spare room and tossed away the key. No, that would be too simple and Sentinel was far too clever for something as crude as that. He had proven to be a master of manipulation to anyone he spoke to, to anyone who met his optics and saw his deceptive smile.
So a more confining idea was concocted.
Ankles and wrists got cuffs affixed, chains connecting them to the corners of the room suspending him above the floor. On his back strong clamps kept his wings from unfolding, unable to fan out beneath him which had always been such a magnificent sight. But they too must be contained.
To top it all off two pieces of metal had been welded over his optics and mouth, ensuring he could no longer speak nor see, leaving him blind and mute.
What remained of his senses were hearing and touch, but he would not be allowed any touching of his own. That would be reserved for the Primes, a right Zeta did not hesitate to use as he reached out and stroked along the golden plating of Sentinel's outstretched leg.
The touch, no matter how gentle or light it was, plunged Sentinel into a violent flinch, attempting to toss his frame to the side away from the innocent gesture, but the chains kept taut, getting him nowhere and only filling the room with a violent clatter of chains.
Zeta watched as the smaller frame struggled against the immovable bonds, pulling and shaking until he neared exhaustion, fans straining to keep up as he vented rapidly in panic.
Every day he acted like this, but each day the struggle lasted shorter and shorter. There was hope he one day would not struggle at all.
Zeta waited until Sentinel's trashing limbs were slowly sapped of energy and the agitated whirring of his fans started to return to normal, his venting laboured behind the gag covering his mouth.
Another attempt, another test, as a single digit stroked across a cheek and Sentinel snapped his head to the side, still a bit of energy left in him, but the finger followed until his head had nowhere to go.
Zeta cooed and whispered words of calm and praise.
"It is okay, Sentinel, my little bird. I am not here to hurt you," he said and continued to stroke Sentinel's cheek ever so gently. Sentinel's frame had frozen, so unlike his earlier attempts at freedom, but Zeta knew he was simply biding his time, wanting nothing more than for Zeta to leave. It made Zeta's mind wander, reminiscing on the face below the blindfold and gag.
He missed seeing his optics, but the risk was too high, they had to remain hidden, lest their transfixing effect would doom them once more.
He yearned to hear Sentinel's voice but that would be equally perilous because when their little canary sang… everyone listened.
Sentinel's presence had that effect on everyone around him, Primes and Transformers alike.
Sentinel stayed still as Zeta's touch continued down to his throat where a thick slab of gold encircled his neck. Another safety measure should the other bonds ever give in.
It pained Zeta that with this collar affixed to Sentinel's frame, Zeta could no longer enjoy the tightness of his throat. Oh what a delight it was to feel Sentinel ripple and constrict around him. They had of course indulged in each other's frames many times before the songbird's fall, probably the only thing Zeta was certain Sentinel genuinely enjoyed. So it puzzled Zeta why his little canary fought against him so ferociously every day when he knew what was coming. Perhaps the little bird feared the Primes would eventually come and punish him, harm him beyond repair. Of course such a notion was nonsense and he had no reason to fear that, as none of the Primes could ever harm their little aide, their ferocious little bird of prey, not even when he conspired against them as he had. They instead blamed themselves for ever pushing their little canary towards such actions.
But restrain him, that they could do.
"No matter whatever you think we think of you, we will always love you," he told the smaller bot as he caressed him, letting his optics wander over the smaller frame, checking that everything was in order.
A thin tube filled with liquid energon connected to one of Sentinel's wrists, drip feeding him the liquid of life for their species. Not enough to give him the strength to free himself, but enough to keep him alive and awake, in their presence or not.
Zeta had to admit it was pitiful seeing him like this, unable to move, to speak, to see. But it was their only viable solution.
Unless Zeta found another way.
"I know deep inside that you still wish to serve us, you still wish to fulfill the purpose Primus gave you," Zeta whispered into his audials, watching them quiver as they reacted to such a familiar voice as his. "But the others have no faith in me being able to tame you. I wish to prove them wrong."
Sentinel's fans stilled before an unamused sharp vent betrayed how he felt.
That was Zeta's cue to allow his hands to wander over the smaller frame beneath him. With reverence, digits traced every little part of their aide. Joints and vents, armour and struts, gilded details and sapphire blue plating. Their little bird was a masterpiece, truly one of Primus' greatest works.
"A frame such as yours… What a waste to let it rust away in oblivion."
With careful strides he moved around the restrained frame and he placed himself between Sentinel's outstretched parted legs, his crotchplates lining up perfectly with the crotch of their aide. It was all by design. Sentinel's position in the room, the placements of the chains and the height he was placed at, was all so Zeta could have free access to their little bird's frame.
And what a view it was.
Sentinel's array was laid bare before him, no longer any plating keeping it obscured. Plush valve lips, plump between the tender touch of Zeta's digits. A node flushed and pulsing in a dull Matrix blue, responding well to Zeta thumbing it gently, Sentinel's fans whirring a tiny bit more each time.
Zeta's other thumb dipped further down, finding the entrance hidden between the folds, slipping inside with little effort. Sentinel's fans roared for a few seconds, his back arching towards the ceiling.
The tight channel was snug around Zeta's digit, but the Prime knew Sentinel could fit much much more. He still pushed the digit deeper, twirling it around in a circular motion, rubbing the tip of his finger over the many nodes inside.
Sentinel's back arched further, his venting speeding up in tandem with his fans. A foot twitched, telling Zeta he was doing something right, but of course he did. He knew Sentinel's frame like the back of his hand.
Slipping his thumb out, a glob of lubricant followed and Zeta quickly pushed the head of his spike against the opening, smearing the thick oil over it and the surrounding lips of soft plush rubber until it was all well covered. Sentinel's frame always provided them with the best lubricant there was.
Using his thumbs to gently push the largest folds aside, opening up Sentinel's valve like a blossoming bloom, made it easy to push the head of his spike against the narrow opening and watch as the lips and walls stretched to accommodate him, to welcome the Prime like it had done countless times before.
The head popped in soon enough, the walls tightening around the narrow part of the shaft right beyond it before slowly stretching anew as Zeta slid the rest of his spike in after it, the increasingly thickening shaft plates quickly becoming much wider than the head ever was. But Sentinel's valve still swallowed it up, plate ridge by plate ridge, node by node. And those nodes on the overside of his spike could be devious as they bumped against Sentinel's own protruding anterior node on the way inside, making Sentinel twitch and tremble each and every time.
In one slow motion Zeta deposited himself inside Sentinel's heavenly valve, the walls and callipers like a stranglehold on his spike, a sensation like no other, unique among their kind.
A tiny flex of Sentinel's callipers left Zeta release a trembling vent. Their aide was simply too good. It demanded all his willpower not to overload in an instant. But he wasn't doing this for his own pleasure, but to remind Sentinel of what they had between them. Of the good relationship between Prime and aide, between lord and servant, between friends and lovers.
Of what Sentinel had tossed aside when he decided to betray them.
This was Zeta's way of showing him he could still have that. He still had a place next to the Primes. He simply had to accept his place once more.
Zeta took a moment to calm his processor before placing both hands on Sentinel's tiny waist, his digits almost circling the small frame. Underneath his thumbs he could feel and see the bulge that was his spike, pushing the plating of his stomach outwards obscenely.
What a view!
It spurred him on, his hands reaching out to hold onto the smaller frame as he pulled out, watching as Sentinel's back arched again and muffled noises of pleasure left his gagged intake.
Oh how he yearned to hear Sentinel's voice again. His moans were melodic, such a treat to his audials, almost enchanting. And for that reason his mouth had to stay sealed, else the fear of it locking Zeta in a trance could become reality.
This whole debacle almost felt like a punishment for Zeta as much as for their little bird at times. The leader of the Primes had been spellbound by their little aide, and Zeta would gladly admit he missed it.
Which was another reason why he so willingly took on this task of reforming their aide even after the horrific attempt at a coup.
To think he had intended to have the Primes slaughtered? Zeta could hardly believe it, but the look in Sentinel's optics had not lied. The hatred burned bright, no longer alluring and welcoming.
He had wanted to ask him why but he had refused to tell Zeta in the moment, and now it was still too risky to let him speak. But later, when the fight had died down Zeta would dare to ask the question again and hopefully get a proper answer, one that would allow them to avoid this in the future. An answer that would ensure Sentinel would stay happy in his servitude to the Primes.
Zeta almost pulled out completely, leaving only the tip of his spike on the precipice of Sentinel's valve. Sentinel's fans were whirring noisily in the small room, and he was attempting to draw in more air through his gagged intake only being partially successful, making it sound strained. The small frame was struggling to handle the Prime, but Zeta knew Sentinel would handle him well, he always had.
Wasting no more time he snapped his hips forward, plunging the spike deep inside Sentinel in a single quick thrust.
A loud desperate keen erupted from the small frame as he jolted in his bonds, chains rattling all the way to the ceiling, making Zeta brush a gentle hand over the exposed parts of Sentinel's face, trying to comfort the distressed bot.
"Hush, little one," he cooed, drying away a few tears that leaked past his blindfold. "Let me remind you of our love and you will see what you have forgotten."
With one hand on Sentinel's hips for support he pulled out once more, thrusting back in with equal ferocity, his other hand caressing Sentinel gently to comfort him.
"You take me so well," he praised. "You always have with your magnificent frame."
Sentinel continued to keen but it was broken up occasionally by Zeta's brutal thrusts, but quickly enough something else drew Zeta's attention as Sentinel's own spike had emerged from its housing. Zeta saw it as a good sign, that his ministrations were pleasurable, that Sentinel found enjoyment in his actions. He had to be.
It was so much smaller compared to his own, but just as sensitive. No one could fault Zeta for wanting to play with it.
Locking his digits around it and gently tugging rewarded him with a new sound from their little bird, a half choked surprised moan. Perhaps the little aide had not realised his spike had pressurised to join in on the fun?
Either way Zeta welcomed it as it gave him something to do as he built up a rhythm with his thrusts, a hand secured around the smaller member, gently stroking it until full pressurisation.
He continued his thrusts and strokes, pushing and pulling Sentinel and himself towards their climax. Sentinel's fans roared and his own had turned as well, filling the small cell with the sound of excitement, the air shimmering from their combined heat pumped into the room.
With a loud clang, a single forward slam of his hips against their aide's pelvis, Zeta's spike found its place deep inside Sentinel's valve. Transfluid bursts forth, filling the smaller frame to capacity and beyond, overfilling it and spilling out around Zeta's girth.
Zeta held himself there until his overload passed, letting the sensation rush through his circuitry in waves. As his venting calmed down he looked down at Sentinel seeing that his aide had not overloaded yet, something he had to rectify.
He pulled out gently, ignoring the flood of transfluid that splattered to the floor and instead leaned down to close his lips over the head of the small appendage. Sentinel's legs twitched weakly, overwhelmed by the sensation, a titillating sight in Zeta's opinion, urging him to push himself down, enveloping it by warm and wet.
It easily fit in his mouth, long enough to tickle the back of his throat, but far from the size befitting a Prime.
Bobbing his head he let his tongue play over the small appendage, muffled noises of excitement emanating from his little aide on each stroke.
And then he arced his back so delightfully and overloaded down Zeta's throat.
Sentinel tasted like sweet energon on his tongue and he savoured it as he pulled off, listening to Sentinel's venting coming down from his high.
With gentle strokes with a mesh cloth he cleaned the spilled transfluid from around his valve. What remained inside would stay there, act as lubricant for the next day. And the next. And the next after that. As there would always be more.
He left Sentinel hanging in his bonds as he moved towards the door, almost hoping Sentinel would make a noise of longing, a hint that he did not want Zeta to leave. But Zeta knew it was too early in the process. Sentinel was too proud, his spark still burning too bright in his chest, defiance and hate still stewing in his processor.
"Goodnight, little bird," he said and left, closing the door behind him.
Tomorrow he would repeat the process, the same acts, the same gestures, again and again.
And again…