Dusty’s Step-Grandma lives with her stepsister. The widowed ladies do that for economic reasons. The bisexual stepsisters also live together for more erotic reasons.
When he needed a place to stay for one night while driving to Florida for spring break, his Step-Grandma told him he could stay as long as he liked. Because of the old women’s highly pornographic lifestyle, and the horny young man's need for good hot pussy, he stayed longer.