Erik's own mind is unsettled for all the reasons a person might expect, and staying that way, but underneath and alongside of this glow his sense of rightness at holding Charles this way, the curves and muscle of him like a slender, gleaming vine wrapped around and through a worked iron lattice. He smooths back the thickest fall of Charles' hair and rests his lips on his hairline, looking nowhere in particular with half-lidded eyes. "I know, Charles," he assures, and lets the variation lay.
He's not entirely convinced that this is all that has Charles so--unsettled, but since he guards his own desired silences with implacable stubbornness, that too will stay where it is for the moment. Everything that Charles means is welcomed, reciprocated to the extent that Erik can even consciously process as much, and he tries to telegraph that back in the steady ebb and flow of his heartbeat. "If you didn't I'd check you for head injury."
Jokes: they will also happen, and like most jokes they imply a great deal more than the tip of their own iceberg: Charles' ability to talk about how he cares, out loud, to be broadly, blithely assessing of and comfortable in his own silliness, is a gift about as accessible to Erik as telepathy. "I like hearing it," he adds gruffly, and spreads his fingers on Charles' jaw, determined by force of will alone to transmit everything that he feels, even if he won't say any of it.