How can I became Nude without my parents know !?

Becoming nude simply means taking all your clothes off. Sleeping nude is a good way to start, and unless your parents regularly come into your room unannounced and uninvited while you're sleeping then they won't know. If you want to experience nudity other times of the day, it's just a matter of looking for your opportunities in both time and place. When they're both away from home is a good time for you to be nude around the house. If you have places you can go nearby such as woods by the house, a swimming hole where you can skinnydip, a city/county park where you can hang out nude after dark, or some state or federal land nearby where you can go and take nature walks (nude of course), those could be some prime opportunities as well. Just always be cautious, alert, and aware of your surroundings.

Do it whenever there not around , ? Common sense ?

I have my sister in my room !! Help me I really want it