Contains: Non-con/Rape, bondage.
A/N: Written for cousinswar.
Megatron couldn't really say why he'd never paid much attention to the sounds Prime made during these sessions. The mech had always possessed the most incredible voice- rich and smooth and a pleasure to listen to, even if the actual content was utter slag most of the time. Today, however, Megatron was having the utmost trouble trying to focus on anything other than Prime's noises.
He could hear Optimus trying to suppress them, an exercise in futility when he was so obviously and painfully aroused. Little gasps and choked off moans and he could have sworn he'd heard a whimper at one point, and wasn't that a gratifying noise to have elicited from the stoic Prime!
As the duration of Optimus' captivity lengthened, so too did each ensuing session; it was becoming more and more difficult for Megatron to focus on tasks that didn't involve his traitorous brother, something he could little afford. The rebuilding of their homeworld was far more important a task, along with crushing the remnants of the Autobot forces.
It was hard to keep that in mind, however, when Optimus trembled and struggled so wonderfully when subjected to his tender ministrations. Megatron had been working Prime's frame for so long this time that he was close to involuntary shutdown; his systems running so hot that the air around his frame was being distorted by it. Around Megatron's as well, if he were honest. Prime wasn't the only one powerfully affected by these sessions.
Sliding one hand up to wrap around Optimus' neck and keep him pinned to the berth, Megatron leaned down to slide his glossa along the edge of one abdominal plate. His oral lubricants were already hot, yet they still sizzled upon contact. He got half a moan for his effort, quickly smothered but both unmistakable and gratifyingly desperate.
Sighing in pleasure, he kissed his way higher, shifting his frame so that Prime remained pinned underneath him. Megatron had intended to end the foreplay with a proper kiss, but Optimus turned his head aside at the last moment, silently rejecting his advance. It was almost impressive that he was still coherent enough to resist, but the modest show of defiance was enough to dispel any mercy he'd managed to earn so far.
The surge of indignation Megatron felt in response was petty, but fuel enough to convince him to continue denying his prize any satisfaction- even though duty should have compelled him to leave over a groon ago. A minor shift in his grip was all that was necessary to turn Prime's helm back to him, his over-bright optics caught and held by Megatron's own heated stare.
He moved in slowly, deliberately. Optimus knew better than to turn away again, and when they kissed it was hot enough that their mingled oral lubricants steamed.