The author puts forward and justifies a thesis that the lie, as an infringement on the standard of veracity, poses a threat both to the durability of marriage and to the cohesion of family. In order to address the lie as a subject of pedagogical studies, the author addresses the lie in several different scientific disciplines, including: philosophy, anthropology, linguistics, psychology, sociology, history, ethnology and neurosciences. As a result of interdisciplinary analyses the author identifies several aspects in her study of the lie: semantic, typological, etiological (also communicating the results of her studies), cultural, moral, historical and strategic. The main part of the paper focuses on the following issues: the attitude towards the truth while selecting a partner and the development of an emotional relationship (engagement and marriage) and short-term and long-term effects of the lie on family members. The climax and final part of the paper is the statement that disapproval towards lying to those close to us and the respect towards the truth are the factors that strengthen the familial emotional relationship between representatives of one generation, e.g. between spouses or siblings and between representatives of different generations, e.g. between parents and children or between grandparents and their grandchildren.