As i have too many stories going on, and all dormant right now, here's two ideas someone else may want to run with: 1) Celebrity free-use, but the celeb is not in on it. She finds she cannot refuse any request for sex by anyone, at anytime or anyplace. She does not know why she is totally submissive, but no one else, not even family, friends, agents, police, etc have a problem with it. 2) Celebrity humiliation: a celebrity pisses off the wrong person and leads to humiliating exploits.
I'm working on a story for the first one. in a freeuse world, Celebrities actresses have to learn/practice being able to say their lines while being banged so there's a need for fucker standstand-ins and consultants
my biggest problem with free use is that there's no challenge. Characters just have random sex in random places. I think it would be a nice twist if a person was not aware of why she could not refuse. Or an actress who find out free-use is in her contract, and if she refuses, she'll be locked up for contract violation for years and lose everything.
I'm going for a different approach, namely can you actually act in an alleged character while having sex? And why would you expect a challenge? The first premise is the challenge is gone. Otherwise you could have something like this story of mine: https://chyoa.com/story/Freely-used,-unfreely.12134
True Free Use is a literary sexy dead end. Its like starting an RPG on New Game +, without an extra dungeon or double final boss or scaling enemies. It only has impact when you already care about the characters, and you establish they care about themselves. Even then, the high is still fleeting.
The best Free Use can do is consequences, I think. Consequences for the user, or the used. Like - Superman basically has free use, because no one could stop him (pretend no aliens or magic wielders or Kryptonite). So, its his own morality that might stop him, and the consequences would still be real for the subject even if there's no justification, no judicial system or law or moral that might stop him. I tried to emulate this concept in a fantasy world in my 'Epically Overleveled' story, but it never even remotely took off.