Met a person from previous birth. Birth!

Asking professionals from modern and scientific background, we wouldn't endorse your beliefs about previous birth. That is your belief and you will have to deal with it. Regarding the person, if you feel he is trying to flirt with you and probably with some others,  you must be matured enough to understand that he is taking advantage of you for his needs and pleasure. You have to make a choice if you want to succumb to such unethical relationship or keep away by avoiding him.  Do a self-assessment about your own values, ethics, your personal life and happiness that is most essential to you as an individual. There are better things that you need to accomplish and obviously better person who can come into your life. If you want more clarity,  consult a Counsellor in your city