Brother and sister, bound by blood and shared history, find themselves alone and aroused. Their eyes wander, taking in each other's bodies with newfound curiosity. They start to touch, tentatively at first, then with growing passion. The sister guides her brother's hand to her breast, gasping as he squeezes her nipple. He, in turn, feels her hand wrap around his hardening cock. They explore each other's bodies, their inhibitions melting away, until they're lost in a tangled embrace, their moans echoing in the empty house.