In 1991 I was visiting Taichung with my male friend Ranjit and my female friend JF. We went to the place that the guidebook described as “the cheapest place in town” and asked for one room for Ranjit and one room for me and JF.
The hotelier refused to do this, and after a bit of a communication struggle we understood that the rooms we wanted were available, and she was willing to let me and Ranjit share a room, but that JF and I could not. At that point the hotelier's concern was quite legible. We took the rooms and everyone was satisfied.
If I were the proprietor of a cheap but legitimate hotel, I would probably have the same concern: I wouldn't want my hotel to be confused with (or used as) a place where prostitutes go to conduct their business.
My question is: is there a name for that type of establishment? (That is, the type that this Taichung hotel was not?) I think it is different from “Love Hotel”, which I think is understood to cater to unmarried couples who don't have their own apartments, and of course it is quite different from a brothel.
Rik Signes suggests “no-tell motel”, which is closer to what I want, but I think that mainly connotes a clientele of couples who are married but not to each other. Anyway this place was not a motel.