A new study published in Adaptive Human Behavior and Physiology sheds light on the types of infidelity which people consider to be the most severe and unforgivable.

“Infidelity triggered my attention because is a fascinating phenomenon, found in high prevalence across different cultures,” said study author Menelaos Apostolou, an associate professor at the University of Nicosia.

The researchers asked 447 individuals from Greece and the Republic of Cyprus to indicate their reactions to different scenarios of infidelity. Of the entire sample, 35.8% were married, 31.5% were single, 26% were in a relationship, 6.3% were divorced, and 0.4% were widowed.

Having an emotional and sexual relationship with somebody else was rated the most severe and the least forgivable act of infidelity. Using online services such as live sex shows and going to a strip club, on the other hand, were considered the least severe and most forgivable acts.

In the middle, from least to most forgivable, were having a one night stand, having an emotional relationship with someone else, having feelings for someone else, and paying someone for sex.

“Our findings indicated that sexual infidelity was associated with more negative reactions and a lower probability of being forgiven than emotional infidelity. One reason is that sexual infidelity may lead to pregnancy and, thus, potentially have more severe negative consequences than emotional infidelity,” the researchers wrote.

“Not all acts of infidelity are the same. More severe acts are more likely to trigger a severe reaction and are less likely to be forgiven. So for instance, if your wife finds out that you go to a strip club she will be less upset and more likely to forgive you than if she finds out that you have another girlfriend,” Apostolou told PsyPost.

The researchers also found that participants who were older and who had experienced infidelity in the past were more willing to forgive compared to those who were younger and who did not have such past experience.

Apostolou and his colleagues also found that women indicated more severe reactions to infidelity than men, but women were also more willing to forgive their partners. “One possible reason why is that women are more emotionally involved in a relationship than men, which in turn, makes them more likely to forgive their partners,” the researchers said.

“Infidelity is a complex phenomenon for which there are many things we do not know,” Apostolou said. “One caveat of the current study is that people responded in hypothetical scenarios, and so they may act differently if these scenarios actually materialize. One way for future research to address this limitation is to examine actual cases of infidelity and the responses of the parties involved.”

The study, “Reactions to and Forgiveness of Infidelity: Exploring Severity, Length of Relationship, Sex, and Previous Experience Effects“, was authored by Menelaos Apostolou, Anna Aristidou, and Christina Eraclide.