No one starts a relationship with the intention of cheating or being cheated on. That's even truer for marriages—no one in their right mind begins a marriage with cheating even remotely on the radar.

Nevertheless, extramarital affairs happen, and a new study is providing insight into when cheating in a marriage is most likely to happen.

The study, published in The Journal of Sex Research, found that infidelity becomes more likely with time and that men are more likely to cheat in a marriage than women.

Researchers determined that women are most likely to cheat between six and 10 years of a relationship, and men are most likely to do so after 11 years.

The researchers based these findings on data collected from 423 participants.

The participants were asked to rank, according to importance, 29 reasons to resist cheating, and about the likelihood, they would pursue an extramarital affair if provided the opportunity. 

The results identified being female, being more religious, and being married for a shorter amount of time as the three most influential factors in people resisting cheating.

The decision to stay out of an affair was motivated more by internal than external factors—fear of being alone and the desire to adhere to moral standards were found to be more influential in keeping people out of extramarital affairs than concerns for how cheating would impact their kids or partner. 

While it's important to point out that this research was based on participants completing questionnaires rather than the study of real-life outcomes, the findings also provide insight into when exactly a relationship is at it's most vulnerable.

This information should help remind couples to not let their relationship go stale as time goes on—we've got some tips on that.