Supermarion said:

"Fantasy is incredibly powerful and if not confused with reality ought to be harmless."

So do you qualify that absolute right to individual liberty of thought in any way?

Secondly, if exposed/outted through no fault of their own, can a persons private fantasy life ever compromise their real life profession?

This is so huge as some fantasy is illegal and abusive. If one uses fantasy to gear up to such acts then the thoughts are parent of action so to speak. On the other hand we don't choose our most powerful fantasies, so no matter how disturbing, we have the right to think what we wish in the sexual arena.

I don't think a blameless outing should compromise one professionally unless it reveals an actual hypocrisy. But it is almost bound to do so. I can't see your average teacher, vicar, social worker or nurse who have played discreetly wanting to make caselaw in an industrial tribunal. And if people know about your sexual behaviour it would ruin your professional relationship in jobs outlined.