"Shut. up." Shifting as much as he could, which wasn't a great deal admittedly and which turned into something resembling pushing into the finger tracing the bared metal. Then immediately twitched at the slap, given where it'd landed, optics flaring bright and nearly pink for a brief moment.

One part of his systems were still running on "fight", tuned towards defense and offense, but his hands were completely immobilised and he didn't have the strenght to do anything about it. His hips jerked inwards with the hit, bared spike housing rubbing against Optimus' thigh and this... was just making him angrier as well as aroused.

"That has nothing to do with---" Growling, Megatron used the angry rumbling of his engine to disguise what to him seemed like the very loud noise of the inner workings of his ports shifting.

At least he managed to keep them closed, even if some part of him suddenly burned to open them up, to give what he hadn't been able to take himself yesterday after he left Optimus.

"Contrary to what this... might look like, spanking actually does nothing for me," Megatron finally managed to snap, voice raw with agitation, arousal and humiliated anger. The faint throb around the thinner plating of his incomprensively still bared interface, the barest flicker of charge-lightning dancing around the rim of both valve and spike housing, implied either something else, or that Megatron was lying.