Sister comes home tipsy and flirty from a night out, you sneak a peek at her peeing and while she’s occupied you sneak up to her dressing room and pick some creamy, dirty panties out of her laundry hamper. She catches you in the act and is surprised at first but then the idea excites her, she tells you that she has better, fresher panties for you and strips for you. One thing leads to another and your horniness gets the better of both of you and you start playing together