"Donna! You won't believe what Nerys has done this time! I was in Henriks when I saw her trying on this blouse, and—! And who the hell are you? What are you doing in Donna's house?"

"Making breakfast? Who are you?" the Doctor stood there at the kitchen counter, spreading raspberry jam on his nice, warm, fresh-popped toast. "And how did you get in?"

You slapped something down on the counter, where it made a sort of dull 'ding' sound.

"Spare key. Now, who are you?"

"I'm the Doctor, nice to meet you. I, ah... live with Donna and her family. Recent development. You must be one of her friends, yes? I suppose that would make sense if you have a spare key. They're all out right now, holiday shopping. I've been left to 'hold down the fort', as it were. I think they just didn't want to wake me up. Would you like to sit down? I don't think they'd mind me entertaining you until they've returned."

Good lord, did he ever talk fast.