Statistics on Adultery in the United Kingdom (2025)

In the realm of relationships, infidelity is a topic that has long been a subject of interest and debate. A 2015 YouGov survey revealed that approximately 20% of men and women in the UK have reported cheating in their lifetime, with a slight edge for women at 19%. However, it's important to note that these numbers might be under-representative, as people may be less forthcoming about their indiscretions in surveys.

When delving deeper into the topic, it becomes clear that the definition of infidelity can vary. Some surveys focus solely on sexual intercourse, while others include emotional or online behaviors, which tend to yield higher rates of reported infidelity. Unfortunately, there are no current statistics available in the UK that encompass these broader definitions.

Since the introduction of no-fault divorce in England & Wales on 6 April 2022, surveys have become the primary source for insights on infidelity, as formal "grounds" like adultery are no longer required in divorce proceedings. Among those who admit to affairs, common partners include friends and work colleagues.

In the gold-standard Natsal-3 study, unfaithfulness/adultery was among the leading reasons for partnership breakdowns, cited by 18% of men and 24% of women. These numbers suggest that infidelity remains a significant issue in UK relationships, regardless of whether it is formally cited in divorce proceedings.

The debate over what constitutes infidelity continues, with researchers and the public drawing different boundaries. While some view emotional or online behaviors as stepping over the line, others take a more conservative approach, focusing solely on sexual contact. In past polling, women were more likely than men to class signing up to dating apps as cheating.

The British public shows a strong disapproval of infidelity, with 57% stating that extra-marital sex is "always wrong". Moreover, 78% of GB adults believe that infidelity is a good enough reason for divorce.

In Scotland and Northern Ireland, the legal context for divorce is different. While England & Wales have moved to no-fault divorce, Scotland and Northern Ireland still require grounds for divorce, with infidelity being one of the grounds in Northern Ireland.

In 2023, there were 102,678 divorces in England & Wales, with the median duration of opposite-sex marriages at divorce being 12.7 years. Despite the prevalence of infidelity and the strong disapproval from the public, it's important to remember that each situation is unique, and the impact of infidelity can vary greatly from one relationship to another.