Is it normal to want some alone time.

My dad is always home. All I want to do is relieve myself some by masturbating but It pisses me off because I always have to be secretive about it. I either have to masturbate in the shower or at my computer late at night. Always I feel self-conscious because I know he is in the next room and I know sometimes it is obvious what I am doing. Fuck I need some alone time once in a while. On rare occasions he will leave to go to the store or somewhere and I have a few blissful hours of freedom. I can't wait until I get a place of my own where I can freely relieve myself without being self-consciously scrutinized.