I'm aware that prostitution is completely legal there but I don't know. I feel like *she should be the one paying. You know?
I have not been to Germany. But I have been to Austria and perhaps it works the same way.
Odd places with signs in the window called Studio number x.
I suspect these are knocking shops. as I mentioned here once there was a peculiar lady sweeping the same spot of pavement as I on my way back from my trip to Mcdonalds.
I suspect you have to give her a codeword or ask for directions or something.