"I'll show you---nh, displeased, Optimus," Megatron growled, but for a threat, it was sort of toothless, even with the vibrating thrum of his voice. Especially given the definitive, helpless, tilt of his hips into the sinuous and downright frustratingly light touch along his spike and into the gaps.

He muttered the words right up against the metal he'd been sliding his lips over previously, however, making sure to at least let the words vibrate off the spike cover. If he'd had his hands free, he'd have been teasing the cover to Optimus' valve as well, but those were stuck firmly behind his back.

Angling sidewards to slide his tongue along the angle of Optimus' pelvic armour at the gap between hip and thigh, echoing the stroke of a cable, Megatron tried to ignore the hyper-awareness from every sensor just straining to follow even the slightest brush of said cables.

It made static crackle and snap and the teasing touches feel like lightning, but the jacks and the cilia at the end of those cables were so close to the still-covered ports in his thighs.

If Optimus thought he would beg, though...