In an unassuming household, a brother and sister, both in their late teens, find themselves alone and bored. Their mutual frustration leads them to explore each other's bodies, starting with innocent touches that quickly escalate. Michelle, the sister, discovers her brother's throbbing erection and can't resist wrapping her lips around it. Her brother, equally enthralled, finds her wetness and plunges his fingers deep inside. They're interrupted by their mother's return, forcing them to hide their secretive new game.