Incest to beat all incest. Brother and sister have been getting it on between each other for years because they could not find anyone who could satisfy them better than the love they had for each other. The sister had been divorced because her husband wanted a younger girl, so the brother moves in with his sister who had three kids, since he was helping pay some of the bills anyway.
A lonely businessman and a beautiful single mom discuss the best deal ever. She desperately needs a home and financial security for her daughters. He wants a willing wife, and some teen girls to play with.
Brad and Mary find a porn magazine that starts them exploring sexually with each other. Their mother finds out and decides to help them back to the correct path.