Even if he didn't have too much experience of fighting with his own ghosts, Jack's also spent enough time trying to help other people through the dark (Ianto and John Ellis and the man who first carried his name each flash through his memory, men he hadn't done enough for, but all that he could) to be familiar with what it looks like when those ghosts step away--not forever, maybe not even for the night, but for now--to allow some of the guards to drop.

It startles him a bit, the way it did when the original Captain Jack Harkness took his hand, when John looks into his eyes like that--like he's something truly grounding, reliable; the very last things most people who knew him back in Cardiff would think of when looking at him. Hell, he hadn't been trying to be that. He'd been trying to be a distraction (hence the pants), a kick in the teeth to that nasty piece of the past, to remind John he wasn't there anymore.

But somehow, this--the way John is looking at him, relaxes against him-- feels…nicer. Not something his younger, mortal self would have understood, but that idiot hadn't understood a lot of things yet, no matter how much he'd lived through.

"Okay," Jack breathes against John's hair. "I've got all the time you need from me."

And for now at least the thought of all that time, something he'd really been hoping Abbadon would take from him, doesn't sound so bad.