He was seeing it, yes and while it was certainly drawing warmth along his circuits and made him wish he did have the concentration to do as wished for at the moment, Megatron didn't.

It was annoying - an annoyance he'd smothered and kept away, unnoticed - but what they'd just done had dwindled energy and concentration and he could easily recognise where it was going; to reserves that would instead let him be focused and fight with the sort of strength that would be needed should they be attacked.

It wasn't something that could be redirected.

He grunted and his optics flickered briefly as the sharper motions settled Optimus' spike deeper in and while he knew he could drive the mech into overload like this with a bit of patience and dedication applied, maybe he didn't have the power to dedicate to it...

Honestly, Optimus, unless you want to ride me I'm not sure I can give you more than this-- Surprised static slipped out verbally as Optimus managed to get far enough to slam their mouths together, and it took a moment or two before he began to kiss back...

Though with that, Optimus certainly could set his own pace.