Gentle
One more for today. Probably very out of character...gentle is not the first word that comes to mind when I think Megatron x Starscream...
Starscream lets out a strangled cry, optics glowing white with excess energy and overheated plates scorching lines into their shared berth, while Megatron slips one titanic, silver arm underneath the flier's arching back. The movement is welcomed - twitching, overloaded mess that he is, Starscream feels his armour support itself against that huge arm instinctively, barely noticing that he is still screaming with bliss.
His optics short circuit, and for a moment, his processor shuts down entirely.
Seconds, maybe minutes, hours for all Starscream cares, and the black begins to ebb away to reveal a frighteningly large and jagged face looking down at his own. There is passion in the flaming eyes of Megatron, but the half-shuttered lids are content, and the nightmarish teeth are hidden behind a smile. Starscream lets out one of those horribly pathetic mewls - always forgetting that his vocalizer is slower to come back online than his optics - and Megatron laughs gently, tracing a claw over the Air Commander's neck.
That silver arm cradling him makes its presence known once again as Megatron scoops Starscream towards him, as gently as one would a sparkling, and this time, the flier does not chastise himself for the strange purrs and clicks tumbling out his vocal unit. One single, massive talon scratches a line saying "mine" along his back plates, and Starscream shudders, knowing full well that those murderous fingers are anything but this gentle in battle.
A kiss as light as a ghost, a lip component brushing his own like a feather, and with a tinge of regret as recharge takes hold, Starscream wishes quietly that these tender moments would last forever.