"Easy for you to say..." Cliffjumper said with a grimace, but there was no real heat behind those words, just a little grumpy frustration. He shifted a little as Optimus leaned in, but then leaned closer, tilting his helm into the bump when he figured out that's what Optimus was aiming for.

This, at least, was easy and familiar enough, and even if the tiny, sort of rubbing motion Cliffjumper arched into was distracted by his body-guard's next words, there was a - slightly hesitant - hand sliding up the plating beside the grill plates and up, just to feel the vibration from the purring engine.

"Uh... Ya know, that ain't really... helpin'," Cliffjumper muttered, slight little hitch in the smooth humming of his own engine due to both the noise and vibration from Optimus'.