Gaius sizes him up. Certainly not someone he's done business with before but that's not a bad thing. It just means he'd have to go through his own questions too. He might be a thief but he's not stupid an certainly isn't going to do any jobs for undercover police or people who never were going to pay him.

He sucks on his bonbon and watches how the stranger holds himself carefully.

"Depends on who's asking."