Are you over 18? If you are, then your dr cant tell them anything without your permission. If not, when the get teh bill it will say "office visit, brief, expanded, or whatever" It won't have your diagnosis or any details of what was discussed. Also, speak candidly with your doctor when you go in. Tell him about not wanting your parents to know. He's a human being too, and has seen a lot worse, I am guessing!