A/N: Starscream/Megatron. Nonsticky. Tactile. Spark play.

Silver legs shifted on the berth to accommodate the large taloned servo digging its way under pelvic plating. The aerial's sharp intake of air was swallowed down by a mouthplate with even sharper denta. Spindly digits searched chestplate for grooves to hook into, something to hold on to as Megatron's hungry mouth lowered.

A simple nudge of his helm was all that was needed to get Starscream to tilt his jaw and expose his delicious neck. One little bite got his fans going and Megatron was pleased, nudging for more neck to taste.

Starscream wasn't completely passive. He showed his satisfaction by scratching his master's armor, just deep enough to send a ripple through sensornet and maybe a little prick of pain. He knew it had worked by the flexing of the war lord's heavy shoulder armor. Each spike twitched as he suppressed a shudder, dark lavender optics cutting up knowingly to his second on command.

So it was going to be one of those nights. Megatron took the jet's mouth in a rough scrape just as he dragged a claw on the underside of a very receptive thigh plate. Starscream cried out and Megatron claimed it, as always.

The connection of mouths deepened with eager glossa, sending a charge up both their frames. Wings quivered in a noisy little rattle, and Megatron let one of them slide into his palm as he pulled away from the kiss. Optics were level and his smirk was devilish.

The wing trembled impatiently in his servo. He didn't even need to speak. Starscream's scorching frame said everything. Please, please, touch me.

Megatron thrummed his field against his second's. The wing shook so hard it was surprise panels didn't start flying off.

The jet looked about to scream for stimulation when the war lord finally indulged, sliding his servo up the long sweep of metal and flight sensors. Starscream gave a raspy moan and arched. When Megatron stroked downward, the air commander cursed loudly and shuttered his burning optics. Licks of energy fizzled excitedly from his chestplate.

This close, the Decepticon leader could feel the mech's spark spinning wildly beneath plating. Such a feeling aroused a hunger in him that he had not entertained in quite some time. And with Dark Energon coursing through him, he desired it even more.

With a final squeeze of wing plane that made the jet buck, Megatron used one hand to lower Starscream onto the berth. The mech blinked at the change of position, but adjusted nonetheless as his master settled over him.

He revealed the port on his side only to get a deep snicker.

"No, Starscream."

A servo came down to rest upon Starscream's chestplate, sensing the oscillation beneath.

After a puzzled moment of processor working, the aerial gave a nervous laugh, wings trying to flip down behind him but lacking the space.

"... Master?"

Megatron's optics were sharp amethysts of power. He pulled his servo down chestplate in a slow and meaningful drag.

"Open," he commanded.

Starscream hesitated, searching his lord's face, wary of the purple glow from within. His master had grown more restless, more ruthless since infusing his spark with Dark Energon. Every mech aboard the ship had noticed the rough grating to his energy field, the wildness to his optics.

Was it wise to open himself up? It probably was less wise to deny him his spark, he decided with fear marring his field. Fear that excited him.

With red optics closing to apprehensive slits, Starscream shifted his plating apart to reveal a glowing chamber. His spark lit both their frames in the dim room, a whirling comet of light and life.

The war lord gazed upon his prize like a starved beast. A hand slid back up over a trembling chassis, earning an audible stutter of vents.

Megatron only smirked. He had claimed Starscream's frame many times over the vorns. He gave himself fully to his master. But no matter how many times they did this, the jet was always nervous.

"Really now, Starscream..." the gladiator vocalized. A claw hovered before tracing the outside wisps of energy revolving around the spark.

The silver Seeker tensed immediately. Megatron pulled his talon away and the frame beneath him relaxed, plating already squeaking with exhaustion. They'd only just begun.

He moved his claw once more, this time passing the outer arcs of light and slipping deeper into the spark. Starscream's claws scrabbled for something to hold onto as gears ground in a deliciously painful whine.

Megatron looked up from his toy to take in the rolling of crimson optics. He pushed deeper, claw tip just barely scraping the back wall of the delicate chamber, energy gripping his claw. Starscream spasmed, vocalizer cutting off a whimper as his spark spun and ached and filled every circuit with precise and sharp pleasure.

The large gray mech looked down to the spark once more, and without warning slipped a thumb in to hold the spinning orb between two claws.

The jet's mouth opened like he'd meant to scream, but only static erupted from his vocalizer in broken sounds. Charge crackled from his frame loudly and in a convulsion hard enough to shake circuit boards loose, Starscream lit with overload.

Megatron growled and gripped the throbbing spark—Starscream's very life—in his claws. He watched intently as those usually glaring optics flickered, systems assaulting the jet with warnings that he could not even read presently.

He maintained his hold even as overload crashed through him. One little twitch and he could crush the spark, break it into static stardust, reduce the gasping mech under him to a husk of metal and slack wings.

With a dark snarl and a final possessive squeeze he let the orb slip from his talons.

After a breath the plates shifted back up to protect the delicate core, and right over the chamber was the Decepticon sigil. His mark.

It was a claim Starscream could never shake.

A chain he could never break.