Spying on naked sister exiting her room

Description: Back a while ago, I ran into my naked sister in the hallway of our house. Needless to say, she didn't expect that I'm awake that late during the night, so she just yelled and ran away. That is when I realized that she often goes totally naked from her room to the bathroom, and that is when I decided that I'll be ready to see her next time. My room is on opposite side of the hallway so I turned the lights down and crouched down to spy on her from under the door. I caught her naked, again.