I quietly ascended the stairs leading to the second floor and saw the bathroom door wide open and singing coming from inside. I got to the top of the steps and peeked inside the door and saw my step mother just getting out of the bathtub. She had her back to me so she couldn't see me and began toweling herself off. I said "I don't want to startle you, but I can dry your back for you if you like. I didn't hear the door. Yes, I'd like you to dry my back please.