The Doctor set his mouth in a firm line, eyes hard and unreadable, but he decided to choose his battles wisely and remained mum while she argued the subject—quite effectively, much to his chagrin. The last time they'd seen each other he hadn't been given enough time to truly witness the evolution of character Rose had undergone in his absence, and while he was pleased to see her standing on her own two feet and trying to save the world, he might appreciate the determination more if she weren't willing to do it at her own expense.
The subject of the other Doctor was a sore one, and while he didn't have the right to judge—not after what he'd done—it was difficult to stifle the desire to place blame on his other half, especially when Rose stood mere feet from him and his twin was no where to be found. He'd just let her go, the coward, let her slip through his fingers like sands on a windy shore.
The Doctor pointedly decided not to dwell on the similarities between them and saved that conversation for another day. Besides, Rose was here, safe and sound—that was what mattered, wasn't it? He needed to keep these things in perspective, because she was right, he would have made the same decision and he needn't chide her about it like a misbehaved child.
He did his best to reel in that negativity she disliked so much, bit his tongue where he knew he should and tried to regain a more lighthearted mood. Jack Harkness was about! That was news enough to make him grin from ear-to-ear.
“Well, place like this, plucking people from their own respective time-lines, refusing to show up on a map and leaving that much temporal energy just floating about in the atmosphere without a Rift in sight? Oh, I don't think Jack could stay away even if he tried,” he said, the rambling amusement reasserting its self as he rocked from heel-to-toe on white sneakers, chin rising with a brow quirked down at Rose.
There was a reserved sort of curiosity in his gaze when he appraised her. “Behaving himself?” he asked, the corner of his mouth twitching with the ghost of a smile. With Jack Harkness, one never could be sure.