As the others have said, as long as you are living in your parents home, you must live and respect their rules. There really is no argument, smoking is indeed bad for you. The fact that cigar smoking may be "less bad" is not relevant. Once you are out of the house you may or may not decide to continue smoking, then it is your decision. Perhaps you can come to a compromise that allows you to smoke when away from home(fishing, etc) It sounds like you have a good relationship with your family continue to discuss this with them in a non argumentative way.