Starscream's failure

“Failure,” Megatron said. “Again, failure.”
Starscream crouched, meekly, half afraid of what was coming.
“I don’t know why I keep you around. You’re arrogant, backstabbing, useless. Worthless. Well. Worth only one thing.” Megatron stepped in close to Starscream. His access port inches from the jet’s optics. “You know what it is.”
Starscream bowed his head. “My lord, please, no….”
“My lord, please, yes,” Megatron growled. “That should be your only concern, pleasing me. Since you cannot seem to do that on the battlefield….” He pulled one of Starscream’s hands to his access hatch. The jet’s fingers deftly opened the catch, even without looking. Long practice. Megatron smirked. He’d keep Starscream on a short enough leash. He was good at this. Very good. Even his rebellion, his hesitation, served only to arouse Megatron further.
Starscream looked up, one hand cupping around Megatron’s interface module. “My lord, how do you want--?”
Megatron cut him off with a ringing blow to the face that sent the jet sprawling. “You do not know how to please me?” he roared. He threw himself on top of Starscream, tearing the jet’s own access panel open with rough fingers. The jet tried to protect himself, his legs curling defensively. Megatron thrust them down roughly, and plugged himself into the jet’s access port hard enough that the jet’s hips bounced against the floor. Megatron grunted. Starscream’s port felt exquisite, still. The way his whole body, his whole energy field, rippled against Megatron’s datastream. No one had ever responded as much as Starscream.
He pushed his datastream in hard throbs into the jet’s port, his hands catching and pinning Starscream’s wrists down. He forced a kiss upon the jet, his glossa invading Starscream’s mouth, levering his labial plates open. The jet whimpered, squirming against the floor. He knew by now that his arousal was just another way Megatron was tormenting him. He knew his own module would go unattached, his own overload ignored. An object of Megatron’s lust, not his partner. Not his lover. Just his pleasure receptacle. Megatron could almost taste the jet’s frustration and fury and shame. It tasted tart and sweet at the same time, the way he remembered the jet’s own overload tasting. Back before Starscream had lost that privilege.
His datastream thrusts took on a rhythm of their own. His eyes bore down upon Starscream, struggling on the floor. He squeezed the jet’s wrists, hard enough to make him wince. So close. He felt his overload ride along his body, down from his central core and through his datastream to the interface module. He bucked his hips up hard, detaching his module from the jet’s access port with his bodyweight, just as the overload reached his module. “Gaaah,” he roared, energon from his overload spraying across the jet’s chassis in thick purple-blue spurts. His body continued to thrust in time with the datastream pulses long after the energon spurts stopped. He crushed his head against the jet’s chest in the overload, looking down at the spatters of his energon. The jet gave a pained cry, his own body twisting half in desire, half in shame. He hadn’t even been allowed the partial compensation of Megatron’s energon release.
Megatron pushed himself to his feet. “You’re filthy, Starscream,” he said, coldly, though the sight of the jet’s spattered body filled him with a burning pleasure. “You cannot even please me here.”