Smirking against the feel of the valve clenching, Megatron was pleased he'd managed to surprise his Prime. Not that most of what he'd been doing hadn't been surprising, obviously. But especially paying some attention to Optimus' spike and valve.

"Your spike will have to wait." He'd seen the twitch, if barely, and didn't bother to keep the chuckle back as he dragged his teeth around down the rim of the valve, and then pressed his tongue in. The spike would have to wait until he stroked Optimus into overload while spiking him, but he wasn't going to say that.

Even with his tongue still tender and not really healed from having done some damage due to the attention he'd given Optimus' spike earlier, Megatron could feel the slight buzz of the caliphers and fine workings well enough, and in an entirely different way than a spike did.

Twisting his tongue around thoughtfully, it was always interesting to feel the tiny components move minutely, forming themselves around something far softer than a spike. It was what, when he did this, which wasn't often, made it worth it. No matter the sensitivity of a spike, or how well interlocking parts fit together, it was hard to feel out the tiny, individual filaments, caliphers and workings.

Like this, pushing in and then up against the roof of the valve, he could, and he certainly didn't mind getting this... ahem, familiar with Optimus. If there was anyone he should, it was probably this mech, if they could get past the hurdle he'd created with this... stunt.

He certainly hoped so, anyway.