[There's no way he wouldn't see it, even if they weren't so close, really - the shift is so incredibly subtle but it almost jars Keith, in a way he can't exactly understand. When Shiro speaks, his eyes dart down to look at their hands too.]
Ah. [Shakily, almost hesitantly, he lets go of Shiro's wrist again and looks at his palm, stained but dry.] You're right, it stopped.