Public toilets in Berlin will double as sex cabins for prostitutes in a bid to improve their working conditions.
But residents and politicians in the city have blasted the move as grotesque.
Two cabins are to be installed in a trial along Kurfürstenstrasse, the city's largest street prostitution area.
Each will have two doors to make it easier for prostitutes to leave if clients become abusive or violent.
"We know they have two functions. But the second function doesn't have to be pointed out," said one official.
But it is said prostitutes in the city are running out of secluded open-air spaces in which to work.
Residents have recently complained house entrances, underground car parks and even their cellars are increasingly being used for sexual encounters.
Michael Ruthenbeck, a member of a neighbourhood association, has called for Berlin to have an official red light district outside the city centre and away from residential areas.
He said: "These [new] measures won't help residents at all."
And local MP Marcel Luthe told the Berliner Zeitung newspaper: "The authorities in Berlin are merely organising crime instead of fighting human trafficking and forced prostitution."
However, groups campaigning for prostitutes have largely welcomed the decision.
But Olga, one of these groups, said it had hoped the cabins would be for sex only.
It was concerned that the cabins would be cleaned only once a day and would not have alarm buttons.
"We would have preferred cleaner and safer locations for the women," said Lonneke Schmidt-Bink, a member of the group.
Prostitution is legal in Germany and was recognised as a profession in 2002, allowing workers to register for social insurance.
Germany has an estimated 400,000 prostitutes. Most come from eastern European countries.
