The Sangam internal relationship (Agam) is a five-way relationship (Ainthinai uravu) of love. This can be called a consensual relationship. We also know that there is a non-contradictory opposite relationship in life. In such a five-way relationship of love, the opposite relationship is the Parathai. In an environment where women of the Sangam period had adopted the norms of moral virtues such as chastity, fear, shame and modesty, it raises doubts that only certain women lived in a contradictory way. On the basis of moral virtues, this article on Parathaiyar Morality has delineated to reveal the reasons why they lived in such a way of life. The sources from Tolkappiyam and Sangam literature have been used as the resources and justification of the article. The article summarised the trends from the origin to the development of Parathaiyar at the Sangam times. In conclusion, the article summarises the original ideas and sources used in the article.