Is it sexual harassment? From the OPs original post, it sounds like while the female was approached by the former supervisor at work (a job that she didn't like) to become his submissive in return for paying her bills and some cash.
While the original offer while she was an employee certainly would have been considered sexual harassment. The relationship she entered into after quitting would not be.
That the OP describes this relationship as a job it is, in fact, a relationship. A sick one to be sure but not a job.