You found your stepsister trying on a revealing outfit, and she was both scared and embarrassed. Stepsister confided that she wanted to spice up her relationship with her boyfriend, fearing he might leave her. To you, she's stunning and you can't fathom why he would leave. Seeking your opinion, she showed you the outfit, which aroused you. Though shy, stepsister asked you to test out this outfit to make her feel more confident on the date, and you gave her the best sex of her life