He only barely catches the flash of hurt as he's pulling back. And he really doesn't know what he did to cause it. She seems to just want to let it drop though, so he accepts it.

"Understood." Her order should hold him back if he ever snaps like that again. He's satisfied with that at least. He doesn't want to ruin her happiness for her. Neither of them know how long she has and if she wants to pursue someone... he'll just have to stand back and let it happen.

But for now he reaches for her hand as she usually did for his whenever they walked anywhere. He's becoming aware of her habits.