Robert, lounging in his room during their family vacation, finds himself unexpectedly joined by his stepsister Amelia. She enters, flustered and flushed, having just come from a swim. As they chat, Amelia's wet swimsuit clings to her curves, drawing Robert's gaze. He tries to hide his growing erection, but Amelia notices, a wicked smile playing on her lips. She teases him, asking if he's "thinking naughty thoughts." Unable to resist her allure, Robert confesses his fantasies, and Amelia, excited and curious, straddles him, grinding her hips against his hardness.