He'd say it was inexplicable that he suddenly felt like he'd gotten in trouble, but the Doctor knew better. Half-turning to look up at Rose as she settled into the TARDIS, he managed to quirk a grin in spite of the little bit of anxiety experienced. When Rose was angry, he knew, and this was not an angry Rose.
Glancing at the tail of his not-so tin dog, all he could see from his vantage point, he nodded in agreement. "Little bit of credit," he joked back. "I'm willing to share it."
At her suggestion of a break, the Doctor blinked in surprise. Had it really been hours? An internal assessment of how much time he'd actively spent puttering around the ship confirmed it and his eyes widened in slight surprise. "So I have. Huh. Lucky for me, can't get exhausted," which was an absolute lie, but one he preferred believing in.
Tugging at his ear then, the Doctor surveyed the mostly patched up mess of a mess of wires beneath his feet. "Oh, it's... progress, I suppose. Nothing groundbreaking, or perhaps I should say airlifting?" He snickered at his own joke, of course. "I'm all right though, Rose. Don't mind me. Haven't got anything on the agenda for today, have you?"