The grin the Doctor gets in return for the answer is nearly as blinding as the Denevian suns, a twinkle in his eyes warm and happy, because how can he not be happy to see the Doctor. To see this Doctor, the one he has yet to meet outside of Asgard, who comes after his own Doctors, but one who'd become rather important to him during his time here. Jack laughs, cheerful, and comments in return;

"I'm pretty sure you're not the only one who's told you that, Doc. Pretty sure I have too."

And then, without waiting for an answer, he's moving to sweep the Doctor up in a hug. Don't worry, it's a perfectly platonic one, but one full of warmth and love even so.