Some state case law (and even statutory law) makes it possible to sue to amend, or even invalidate (although that's rare) prenups. This is most frequently seen in circumstances of domestic violence. I would think that FL isn't much different in this regard, although I'm not precisely sure what the law in that state with respect to this issue.
Why do you keep taking about FL?
I wonder if the argument could be made that there was domestice violence in the sense that he exposed her to god knows what due to his unprotected sex with some many women, including a porn actress. It would be interesting approach.
Who knows, I hope she takes him to the cleaners.