Luckily for Q, once the door is open he's greeted both by an enthusiastic (although clearly put off) dog, as well as cigarette smoke. John's thanking his other self for that at least -- he's clearly a smoker. John's been helping himself.
"Firmly British?" He has to ask, he might be an asshole, but he's not just going to pawn the dog off on any willing stranger. Just this willing stranger, apparently.