Watch Stepmother's Purpose for Free: How to Stream the Movie Online at 123Movies. . One man divorces his wife and falls in love with a woman who frequents the bar alone. Even if they’re both aware that the man has a son and the woman in the bar has a daughter, they decides to live together. One day as she is left alone, the mother cleans the house and accidentally sees the paperwork, and finds out that the house and all the properties are inherited by her son. With her eyes on the property, the following days, she tries to seduce her son by exposing her body.