Sarah.

Your sister had heard soft noises coming from your bedroom, so she was concerned for your well-being. But when she peeked past your ajar door, she saw what looked like you and Jeannie having sex. If that wasn't hot enough, Jeannie seemed to whimper something. Maybe dirty talk... Sarah lean her head against the wood of the door, getting horny from watching you two. With her mouth slightly open. One arm hung at her side while her other hand rubbed her chest in slow, small circles. "Oh, Johnny..." She was entranced by her brother being so loving and passionate; her heart started racing and her hormones raged. "I'll be a good little maid... Let me clean you up, take care of you. I love you..." She groped her breast through her uniform, and rubbed along her thigh, enjoying the gentle sensations. "I'll do anything..." she panted softly. "Anything at all, for you, Sir..." Right then, she quickly covered her mouth; something about the way she submissively thinks about you in that way gets her excited. But more than that...? It made her feel complete to serve you, with a loving heart now. She left quietly as she could, leaving you and Jeannie to your business. As she passed by her mother's room, she could see that she was becoming obsessed with bondage: clamps, toys, whips, etc... Looks as if she wants to show it to Johnny, also obsessing over having sex with him all the time. Sarah only hoped, as she left the doorway, that her mother gets better. Soon...