1 / 9According to research conducted by Boston University sociology professor Deborah Carr, up to 25 percent of married men admitted to sleeping with someone other than their spouse during their marriage. 2 / 9However, it's not just waning attraction that prompts men to be unfaithful—there are countless other reasons men stray.3 / 9Hiding a cell phone or taking it to the bathroom or even on the shortest trip to take out trash is a red flag. It means that the partner doesn't want you to see something4 / 9If your partner suddenly seems to have no interest in sex, despite being in decent health both physically and mentally, it's often one of the telltale signs your husband is cheating.5 / 9Between the guilt of having an affair and the waning attraction to their spouse, many men will make virtually any excuse to stay out of the house. In some cases, this means logging long hours at work—or at least pretending to.6 / 9Emotional distance: If there is someone other than you in your partner's life, there will not be much exchange of thoughts or emotions.7 / 9When your husband suddenly has a new reason to look good naked, don't be surprised if he's suddenly hyper-aware about the calories in his favorite foods or the lack of definition in his calves.8 / 99 / 9