If you have a bathroom with a window, I think it's much less risky just to smoke in there. Put a towel under the door, turn the shower on hot, open the window, and smoke a few bowls. I'm just guessing that your parents are less likely to walk in on you in the shower than they are to walk in on your in your room. It also helps to have febreeze or ozium or some sort of good air freshener. Your parents might start to get suspicious if you keep taking 45 minute-long showers every night though.