Stopping short of going through their WhatsApp or hiring a PI, there aren’t many ways to spot a cheater. But while they don’t exactly walk around with a sign on their head saying “BTW, I’m having an affair,” the truth isn’t actually that far off.

Scientists have found that adulterous behaviour could be written across people’s faces after all – because the shape of our faces correlates with whether someone is likely to cheat on their partner.

The researchers, from Nipissing University in Canada, asked 314 students who were all coupled up to complete a questionnaire about their relationships, sex drive, sexual orientation, the chances they’d consider cheating, and how comfortable they are with casual sex.

The researchers also took photos of each student, in order to analyse their facial width-to-height ratios (FWHR).

They found that people with a high FWHR – square wide faces – report a higher sex drive, and are more easy-going when it comes to casual sex. They’re also more likely to consider being unfaithful in their relationship.

Lead researcher Dr Steven Arnocky, said: “Together, these findings suggest that facial characteristics might convey important information about human sexual motivations.”

Previous research has found that square-faced men tend to be seen as more aggressive and dominant, as well as more unethical and more attractive than those with thinner, longer faces.

This is because facial proportions correlate to different levels of testosterone during particular periods of growth and development, such as puberty. Testosterone plays a part in forming a person’s sexual desires and attitudes as they grow up.