In the dimly lit den, the siblings' eyes meet, a silent agreement passing between them. Michelle, the elder, licks her lips, her gaze fixed on her brother's crotch, where a bulge tentatively grows. She's been fantasizing about his thick cock, and now, with their parents away, she can't resist the urge to tempt him. Their hands tentatively explore each other, hearts pounding in sync. Michelle guides his hand to her wet panties, gasping as he rubs her clit. She unzips his jeans, freeing his hard, throbbing dick. They're teetering on the edge of no return, their breaths ragged, when a floorboard creaks upstairs, freezing them mid-act.