Cannibal Taboo (2006)

Cannibal Taboo tells the story of Janet, a young woman raised in the wilds of Africa who is rescued by explorer Cliff Hendricks. When Cliff contracts a rare blood disease, Janet must leave her jungle ways to care for her husband and their four children. The bulk of the plot occurs when the youngest son, Paul, is about to have his twenty-first birthday. His brother Luke, a successful professor, returns for the celebration. However, things are not so simple in the Hendricks household, since fourth sibling Matthew disappeared on his twenty-first. Moreover, Paul and his sister have an incestuous relationship, and Janet is harboring a terrible secret.