Rogue frowns slightly, not understanding. If he wasn't upset about the way he'd reacted physically... There are a thousand possibilities but not one of them stands out among the rest. If he won't explain it to her now, maybe he will later, when they've both recovered from their exertions.

With him leaning into her, she slips one arm around behind his neck; he's too big for her to be able to reach all the way around him like this, but that's okay. With one hand, she slips her fingers into that gap in his forearm, using the same pressure she had on the cables at his neck to massage the wires and cables here. Even pressure, then a pinch, a roll, listening to the sound of his engine. And with her other hand, she finds one of those crests, caressing the sensitive metal with the pads of her fingertips.

"I've got you, sugar," she assures him quietly, something a bit sultry in her tone as she enjoys the feeling of his engine rumbling through her where they touch. When she finds he responds to something in particular, she does it again, a bit firmer, faster. And then, because she has a hunch, she adds in a more pleading tone, "Please, Knock Out. Just let go."