He sinks into John's touch like it's home, grips him painfully tight around his ribs for a few seconds as he buries his face in the familiar, safe darkness.

Then there's a muffled, tight but deeply grateful, "Thank you, John."

And he allows himself one last squeeze before he peels back, a slightly stronger smile offered until he's turned away and walking upstairs, and when he's under the covers he curls up as small and tight as he can. Like if he manages to be small enough then he'll shrink out of existence and Charlie won't ever have to look at him like that ever again.