http://www.internationalsexguide.nl/forum/showthread.php?3758-Germany.-FAQ
https://www.iheartberlin.de/funny-german-sex-words/
There was a new prostitution law in 2017 that made it illegal to advertise bare sex too.
https://www.dw.com/en/germany-introduces-unpopular-prostitution-law/a-39511761The new law prohibits flat-rate brothels and gang-bang parties, in which a sex worker must service several men concurrently. Also, sex without a condom is prohibited. Furthermore, clients who knowingly make use of the services provided by people who have been forced into prostitution will be penalized.