But when researchers interviewed 547 Norwegian and 216 American university students, all of them heterosexual, they found that the “clearest gender-differentiating factor” for regret after casual sex is who made the first move.

They also found that women feel less regret if the “partner was skilled and they felt sexually satisfied”. All the participants in the the study undertaken by researchers at the Norwegian University of Science and Technology (NTNU) and the University of Texas were aged under 30 years.

“Women who initiate sex are likely to have at least two distinguishing qualities,” says Prof David Buss from the University of Texas.

“First, they are likely to have a healthy sexual psychology, being maximally comfortable with their own sexuality.

“Second, women who initiate have maximum choice of precisely who they want to have sex with. Consequently, they have less reason to feel regret, since they’ve made their own choice,” he adds.