The people, all unmarried, were asked if they ‘had sexual relations with someone other than your partner since you began seriously dating’.

Those who had sexual relations with someone other than their partner in the first relationship were three times more likely to have sex with someone other than their partner in their next relationship, compared to those who did not, the report found.

People who had been cheated on in one relationship were also ‘twice as likely to report the same behaviour from their next relationship partners’.