The Doctor smiled as she touched his fingers, and nodded eagerly as she decided that the new hand was normal. He usually tended to forget it had ever been chopped off in the first place. He was caught a little off guard when she hugged him - he wasn't quite prepared, and so at first he just stayed stiffly in his position. It was a couple of seconds before he hugged her back, and once he did... he could have just held on forever, crying into her shoulder no doubt.
He held a little too tightly, breathing in her scent; he didn't even respond to her thanks, just bit his lower lip to stop himself from saying something he'd regret. He was reluctant to let her go as she pulled away, and he couldn't seem to help the sadness in his expression as she did. He didn't even smile as broadly at her statements about Jack. "Been more trouble than it's worth, that hand," he commented quietly, sinking back into the couch with a strange dull ache in his chest.