After reading a pamplet on incest a brother and sister attend a meeting. In order for the brother and sister to join the Incest Club, they both must seduce a member of their own family. While the sister has her heart set on EVERY member of the family and the brother has his heart set on his mom and sister. With all the cummings and goings even the youngest teens see what is happening and join each other for a little tryst.
Watching other couples through a telescope leads a mother and her son to each other's arm as well as pave the way for a three way relationship with a girl they used to watch.
Dr. Alex Stone feels awkward talking to his son about the birds and the bees, so he gives the boy a picture book. When the boy's sister interrupts his reading, they learn a few things together.