The Doctor regarded the Master silently for several moments, then he finally settled on a smile. "I've lived through pain I never thought I would this regeneration. I brought you back from the dead and if I could tear a wall down between universes, I'd do that, too. I don't need to snap to be crazy. Wouldn't call that harmless."

He turned to look at Jack, flashing him a brilliant smile. "Though I'll take 'cute'." With a shrug he gestured toward the freezer. "Help yourself, Master. I've asked you to eat ice cream, certainly won't stop you now."

Instead of letting the Master's words get to him he leaned back in his chair again, putting his feet back on the table. "Maybe if you eat enough you'll grow big and strong like my Jack."