He's not surprised when it happens, and he slides up in the tub without hesitation, sighing again as he feels Neil pressed against him. He leans back, eyes closed, one hand curled against Neil's shin. But just curled, unable to do much grasping. His hands are always the last to go, folding loosely in on themselves, difficult to use unless he really makes an effort.

Sometimes it amazes him, how Neil can coax him into this state without doing much at all. But it shouldn't. It's a logical progression of conditioning, and he was already primed for it anyway. So he has no room for amazement now. Just the rise and fall of Neil's breathing against his back.