I have a work trip that ends in a Wednesday afternoon in Frankfurt  
I originally booked through Saturday  

I plan on visiting a fkk Wednesday evening and then leave Thursday morning to …..
Help me decide where I should fly Thursday morning to spend a night with the only goal being fucking  
I’m ok with 2 nights in said city or open to flying somewhere new Friday morning and playing there Friday night and changing my return Saturday from that city

I’ve considered Zurich  
What do you guys think

I am familiar with two out of the three main FKK establishment in Frankfurt. No reason to believe that the third one is not at the same level.

Stay in Frankfurt, make sure you have some vitamin V with you and fuck those nights away. You won't regret.