Fifteen year old Betsy needs her older brother's help with a homework assignment and Troy reluctantly agrees to assist his little sister, only to discover that the bonds of blood are no match for the passion their hearts alone can share.
A young boy is caught by his father licking his younger sister and is immediately sent away to live with his father's friend. The friend's wife reads the note carried by the boy and saves the boy for her own desires. Thus begins his real sexual education.
Frank Armitage lost his wife to cancer some months ago and his family, especially his elder daughter Caroline, have anxiously been waiting for him to get over the worst of his grief. Caroline, her sister Abby and her daughter Mandy start work to bring new life and vigour into Frank's life.
When Tony's parents went away for a long weekend, they left their kids at home. After all, Tony and his two sisters were pretty mature teenagers. What could possibly go wrong?