An adult brother and sister (with flashbacks to their teen years) and his two teen daughters and their life together, swinging with neighbors, until they come to realize that they are more than just brother and sister. Note there is bisexual male/male sex and some watersports.
A mother who made love to her son the night before is seduced by her daughter, who is also her brother's lover, when the daughter confronts her mother about the incestuous affairs.
Fourteen-year-old Linda's tryst with a fifteen year-old boy results in pregnancy but not marriage. Her baby son, after birth is taken away from her. However he returns fifteen years later and satisfies her cravings.