He's seen Shinjirou in pain before, and something about his behaviour now strikes him as odd. It doesn't take very long to sort out his intuition into a more logical, more concrete thought: Usually Shinjirou is desperate for affection even as he tries to hide away - this time, he seems entirely preoccupied with hiding.

Are you alright is a useless question considering the circumstances. Maybe the best course of action would be to let Shinjirou hide away as he so clearly wants to do, but still, Jade hesitates. It's such a big change that he wonders if he's read him wrong.

"You can stay on my bed, you know," he suggests, expression neutral. "It's probably best if you don't move around too much."