"Yes, yes, we'll all have a good self-pity," the Doctor said, but he didn't pull back from the embrace.

For all that the Doctor was chastising Jack, he was thinking the exact same thing. Jack should've been off somewhere, not regrowing his lower body because of the Doctor. If the Doctor had just stayed in the flat back in Cardiff, maybe pretended to be asleep or something so they wouldn't have to talk about the with with conversation, maybe if he'd just thought before he'd acted...

And a small buzz in the back of his mind said that maybe if he agreed to what Jack wanted instead of pulling away out of fear...but that was a voice not to be listened to.

"I don't know how long night lasts here," he said. "You should rest while you can. I'll stay up, keep an eye out."