This, Starscream decided, was his best plan ever.
Below him, the Autobot leader shifted and was rewarded with a smack on the shoulder and a hissed "Stay still, you idiot!" as Starscream pried at the seam between those windshield panels. Optimus, for his part, only increased his grip on the seeker's hips, those blunt fingers digging into delicious seams between pelvic and leg armor.
"You're certainly… hnngh… eager…" Optimus groaned, a hint of a smile in his voice. Starscream narrowed his optics. The Autobot was teasing him. He hated being teased.
"There's no reason to draw this out, is there?" he snapped, scraping along the seam with deliberate slowness. Optimus squirmed a little under his touch – which didn't bother Starscream as much when the truck was murmuring his name so very nicely. It was almost like begging, and Starscream liked begging.
"The great Optimus Prime," Starscream purred, unable to resist. "Reduced to writhing underneath a Decepticon. How appropriate." Optimus seemed to rouse himself a little, at least enough to give the seeker an arch look.
"Reduced?" the Autobot asked. "I don't think you know how this is done, Starscream." And before his partner could hit him again, the chestplates finally – finally – parted, and Starscream was distracted by the bright, healthy light of a spark shining through. A distraction that Optimus used to full advantage.
Starscream hissed at the hands that left his hips – then groaned appreciatively when they reappeared on his wings, surprisingly light and gentle given their size and the power he knew they held. "Mmm, good," he murmured, and only belatedly realized he had leaned forward over Prime's open chest. That was fine, he reasoned distractedly. A little less control than he would have liked, but it was getting the job done. As the Prime's plating fully parted and revealed the spark underneath to the open air, the Matrix gleaming around it, Starscream had his first doubts about this plan of his.
He was interfacing with the enemy. An enemy that wasn't really an enemy at the moment, technically, given the fragile ceasefire that stood between their factions – but certainly not an ally.
As if the Air Commander had allies to begin with.
Of course, this wasn't something so foolish as a whim, or because he found the large, heavily-armored mech attractive – though it didn't hurt – but because he had a plan, a very good plan, no matter what his wingmates thought of it. This was why he never told them anything anymore…
Optimus Prime made a noise that distracted Starscream from his thoughts, and the Decepticon looked down to see Optimus watching him expectantly. Slightly unnerving. But at least the truck knew his place and didn't dare touch the glorious Starscream to pull him down, or anything so bold. Still, it was a demand of sorts, and if Starscream didn't do something soon, the Autobot would become suspicious…
So Starscream forced a devilish smirk as his canopy glass split down the middle and slid inward into his frame, and the multitude of other pieces rearranged themselves to expose his spark. The dark, hidden room of the Ark that they occupied was now dimly lit by both orbs, each spark's light reflected off the metal of the other's frame.
If Optimus recognized the nervous tension in Starscream, he ignored it in favor of admiring the exposed spark. "Beautiful…" he murmured, and Starscream chose to be flattered, wings hitching up a little higher and twitching self-consciously. Hesitant no longer, the seeker placed his hands on either side of the truck's head and leaned down, leering.
"Again," he demanded, voice quiet and rough.
"Beautiful."
Starscream fell.
When Starscream woke, he knew it was a success. There was a blip on his HUD; critical alert, a low-level drain on his energy reserves, medical attention required. He dismissed it, sitting up with a grunt. Did he care that he was sitting on Optimus Prime's legs and probably compressing vital fuel lines? Not at all.
Of course, he could easily extinguish the Prime's spark where it lay, wide open in the chest cavity of the exceptionally stupid Autobot. But… it could wait. Starscream wasn't known for his patience, but he could be patient – when the reward was high enough. The image of Optimus Prime brought to his knees was enough to stay the seeker's hand. For now.
Instead, he closed the Autobot's chestplates manually and left his own open. After all, there was no reflective surface in here, and no other light source than his own spark, so Prime's windows would have to do.
Optimus woke to the sight of Starscream, chest still open, examining his reflection in the Prime's plating. Before he could make a sound, the Decepticon spoke.
"You've sparked me." It was said without emotion, without looking at Optimus, but staring intently at his reflection – an image that Optimus could now see was that of a tiny, newly formed speck of light orbiting around the Decepticon's much larger spark.
He was struck momentarily dumb, and it showed. The situation didn't improve when Starscream practically shoved his spark in the Autobot Commander's face. "What? You need more evidence?" the seeker barked irritably. "Expect me to submit to your medic's invasive examinations? My, won't that be humiliating! You'll have to admit that you rubbed sparks with a filthy Decepticon."
"You're not a filthy Decepticon," was all Optimus could think to say, his processors reeling to keep up. Starscream sat back and sneered down at him. "Of course I am!"
A quiet part of Optimus Prime's mind dearly wanted to say 'Well, if you insist,' but he refrained and instead tried to gather his wits. "You needn't submit to examinations if you don't want to," he said instead, shaking his head and sitting up, forcing Starscream to sit further back on his legs.
"Good, because I won't," Starscream snapped. "I don't want filthy Autobot hands contaminating my spark."
"They apparently already have," Optimus pointed out helpfully. Starscream's glare did little to silence him, unfortunately. The Autobot at least looked a little chastened. "What do you want to do?"
Starscream gaped silently for a moment. "What?" he finally managed. Optimus bowed his head.
"This was accidental," the Prime admitted – the fool – and folded his hands together in his newly vacant lap. "If it is your choice… I would send the sparkling back to Primus for you." Starscream's optics widened, wings flared out aggressively.
"What?" he screeched. "Was I so good that I knocked some circuits offline? You're Optimus Prime! Since when do you perform sparkling exterminations?"
"Since Megatron perpetuated this war millennia past when it should have ended, and my soldiers are not always as wise as they should be."
"Hypocrite," Starscream spat. Optimus merely shrugged helplessly. But, recalling his purpose here, Starscream calmed after a moment and fixed Optimus with a wary, sideways look, sealing his chest shut as if half-suspecting that the Prime would terminate the sparkling without asking a second time.
"I… want it." It was true enough. In a way. Optimus nodded with something like relief and Starscream relaxed.
"I'm glad to hear that," Optimus said. Starscream could hear the warm smile in his tone, and hated it. "I will do everything I can to accommodate you."
"Oh," Starscream purred darkly, leaning forward to press Optimus back onto the berth with hands on either shoulder. "I know you will, Prime."