The creaking floorboards outside their shared room signal Dad's approach. The sisters, entwined and breathless, freeze, then slowly, deliberately, resume their illicit dance. They've always been close, their bond deepening into something darker, more carnal as they've grown. Now, with Dad mere feet away, they push each other to the edge, their moans swallowed by the soft hum of the old house, their bodies slick with sweat and desire.