Doubts about infidelity often arise when a partner becomes distant or starts behaving differently. While many relationships naturally go through insecure phases, some patterns raise concern.

Private investigator Ray Ranno says there is one common behavior he often notices before men begin an affair. Based on years of surveillance work, he claims consistency matters more than isolated incidents.

According to Ranno, one early sign is suddenly cleaning the car. Men, he says, often prepare their vehicle before meeting someone else, especially since they usually insist on driving.

Ranno’s career spans work with attorneys, police departments, and private clients, and he says he has caught thousands of cheating spouses through discreet observation.

Investigators stress that no single sign proves infidelity. Changes in behavior can apply to both men and women and should be viewed in context.

Experts note that a sudden interest in doing one’s own laundry may signal someone trying to hide evidence like perfume, lipstick, or stray hairs.

Mileage changes can also be revealing. Extra miles that don’t align with work or routines—or fewer miles than expected—may suggest secret meetups.

Other common signs include increased phone privacy, unexplained spending, and sudden attention to appearance. Together, these shifts may indicate something has changed beneath the surface.