well, to add on to what someone has mentioned earlier....
just keep the contact with him as minimal and professional as possible. serious, business-like and no smiling. politely and firmly reject all offers of dinner, dates or presents. do not answer any personal emails, cards, messages, calls etc from him. If he talks mush, excuse yourself and leave immediately. Keep all personal effects locked away, especially anything that has the scent of your perfume.
good reminder.
i'll start tomorrow.