Depending on the circumstances, someone might decide to hire a private investigator to learn whether their suspicions about their spouse's infidelity are correct. The person may believe the spouse is cheating but doesn't have any evidence to prove this. Since many people will not tolerate this behavior, they want to find out whether an affair is actually happening and file for divorce if it is.

Circumventing Discretion

Without a professional's expertise in investigating while not being noticed, proving that a spouse is having an affair can be difficult. The two might be extremely discreet. They might only see each other when the spouse is out of town on business. Even if an acquaintance has mentioned seeing the person out and about with an unknown individual, there likely is no evidence of a romantic involvement. 

Compromising Behavior

A private investigator may devote a substantial amount of time to following the client's spouse to catch the person in compromising behavior. The investigator also needs to get photographic or video evidence. The spouse sharing a hotel room with someone else is an example. If they spend all of their time in another city, it may be easier to photograph them at restaurants and other public locations.

Social Media

This skilled investigator also may be able to find evidence in someone's social media accounts. A friend of the spouse or the romantic partner might have posted pictures on social media. The couple may be unaware of this or believe the pictures are safely hidden because they are locked behind privacy settings. That isn't always the case, however.

The Possibility of Other Misbehavior

The investigator may find out about other misbehavior connected with the infidelity, such as illegal drug use or funneling of money into private accounts. 

Money that seems to be disappearing might be spent on the affair. The spouse might routinely pay for expensive hotel rooms, dinners, and gifts. This individual may even be renting an apartment so they have their own private place to meet. The lover could be living there. If the couple likes to indulge in cocaine or other illicit drugs, that's another reason money is vanishing because of this relationship.

Use of Evidence

Any evidence obtained not only factors into the decision-making process about divorce, but it could also strengthen the case in efforts for child custody and spousal support. Evidence also will undermine any efforts by the spouse to contest the divorce.