I went to a place once which seems so-so (in Hertfordshire), a Thai girl on the desk, and then another who actually gave me the massage, plus an EE man who turned up later - I was told I was earlier than normal, so not the normal desk person.
However, they moved from this huge place, to a private house. This time when I went in another big EE man, loads of tattoos, and 'attitude', was on the desk. I got the impression that he controlled the girls. Luckily, there was a problem, so I made my excuse and left, but I had the feeling that these girls were not there freely. I didn't call the cops, maybe I should have done?