If They Cheated Once, Will They Cheat Again? A yet-to-be-published study by Denver University grad student Kayla Knapp looked at the relationships of 484 unmarried 18-35 year olds and found that people who had cheated on a partner in the past were 3 New research confirms everything your mom told you about «once a cheater. » Many unfaithful partners tend to be repeat offenders. 5 times more likely to be unfaithful in a subsequent relationship. Yikes. (The study didn’t account…