A man has been married to his wife for seven years. The couple has two beautiful children, a fabulous home and appears to have the perfect marriage. One afternoon, after her husband leaves work, she decides to stop at the local bar. The man is sitting at a table in the corner of the room. Not long after he arrives, a woman approaches him. He asks the man if he can join him at his table. The two seem to have a lot in common and enjoy each other's company. The woman asks him if he would like to return to his apartment. He didn't argue with his wife today. In fact, she surprised him with a love note in his briefcase. Their sex life is pleasant, frequent and without complaints. The couple currently has no financial problems. Despite this, why did the man decide to leave with a stranger and cheat on his wife? A lot of research has been conducted on the topic of infidelity. Marital therapists have reported that more than half of the couples they counsel are in therapy because of infidelity (citation Atkins, Jacobson). Therapists also consider an extramarital affair to be “one of the most harmful relationship events and one of the most difficult problems to treat in couples therapy” (whisman predicting sexual infidelity…). Some therapists estimate that 50% to 65% of couples seek help after an episode of infidelity in their relationship (Atkins, Jacobson, & Baucom). Identifying the reasons for this problem is essential to its successful reduction. Infidelity is not a new phenomenon. However, until the late 1970s, research on the topic was scarce (Drigotas & Barta, 2001). In an attempt to determine the root cause of extramarital affairs, numerous factors were examined, the focus of the article being indications and implications. In a future study, a satisfaction questionnaire could be included to examine a participant's current marital satisfaction prior to exposure to their condition. A study should be conducted using an older sample of male participants to see if the results would be different due to decreased testosterone levels in that age group. Additionally, future researchers should consider investigating homosexuality, testosterone, and infidelity. There is no research addressing homosexuality and testosterone. and infidelity. Therefore, future research should explore these aspects. Research dedicated to the biological reasons for infidelity represents an important and necessary contribution to reducing the global epidemic of divorce. Understanding the effect (effect or affect?) that testosterone has on infidelity is another step in this process.