I would agree that ignoring is your best option at this point. The lines of appropriate behavior have definitely been crossed. I would consider putting something in writing to your boss regarding your wishes just to cover the both of you. Harassment is illegal and grounds for a restraining order if it should come to that. Keep records of all inappropriate contact/behavior just in case you should find yourself needing proof of it in the future.
Sorry you're dealing with this. ((()))
L