His son's wife seems chaste and pure... However, the father-in-law accidentally finds out that this is all just an illusion, and that she is actually quite the slut. From that day on, the father-in-law loses all sense of reason and seduces him, leading to a passionate affair that continues day after day. The wife, who has forgotten her devotion to her husband, becomes obscenely devoted to her rendezvous with her father-in-law, going crazy with pleasure...