I've never found prostitutes to be secretive. Anyway, the first job was a bloke going to ride one and he didn't mind telling me that. The second was a prostitute on a house call, apart from picking her up at a brothel in Northwood and having driven her before, the SMS she showed me with the address contained a chain of correspondence including the call out fee. The more astute (generally Eastern Europeans) often ask you to wait until they go into the house, obviously gives a little extra security in letting the client know that someone has seen her enter the premises.... that's something I generally do without being asked anyway but if asked I'd be more overt.