I have a porn setting but cant figure out a story, tips on finding a story?

I have been struggling as of late. I have had this really interesting setting in my head for awhile noe so I spent time building its aesthetics and structure and such but I'm trying to figure out the story that can take place there.

What themes to explore? What happens to the characters and who are they? I obviously have very very loose things I know I want to do but I'm at a point where I think coming up with a whole new story for the setting is best.

Does this happen to anyone else often? How many of you have a setting before a plot idea and most importantly I'd love some tips ot advice on ways to brainstorm a story.