'Sweetie' again. Five bristles and flashes another tight smile. He might not be centuries old, but there's a reason he finds their story so easy to believe. The Doctor gave the impression that he was the only time traveler that survived where he comes from, and yet here's his wife, who has somehow been alive for as long as he has. Presumably.

"Longer for him. Does that mean he keeps coming back to the same time for you, or do you regenerate like he does?" Apparently that was the logical follow up to the stereotypical 'how long have you been married' question. The Doctor liked to ramble, both versions he's met actually, so he's banking on her being just as willing to share.