Changes in work habits, an unusual demand for privacy, mysterious phone calls, spending a lot of time with a new friend and suddenly starting to tell lies are some common signs of a cheating spouse. Usually, the injured spouse's own new fears, suspicions and intuitions provide some reasons to investigate.
Words make good clues that something is wrong, such as when the cheating spouse insists upon needing some space to sort out feelings. A cheating spouse may also talk about loving the other spouse but is not in love. Behaviors of a cheating spouse often include an inability to account for missing time or getting caught in lies. Sometimes a cheating spouse cannot account for missing money.