I noticed a reference to the CFI Code of Conduct. . .
The code of conduct is real simple. . .straight from the FOI and professionalism.
It appears extremely clear to me you've made your feelings known to this individual, and that after repeated comments/advances he hasn't waken up to the fact that you're not interested (for I can only assume a number of reasons) due to the obvious professionalism issue and conflict of interest in the long run.
If it continues I'd deal with it myself, without my Chief CFI or Asst. Chief telling me what to do. If I were in your shoes, the next time, or if you're already tired of it. . .I'd tell him to begin looking for a new instructor. But of course, to back yourself up, find another student you can take on so you don't lose any income.