After decades of marriage, some couples have gotten so used to being unhappy together that they hardly notice it anymore. They go to work, come home, eat dinner and spend the evening on opposite ends of the couch.The divorce rate among Americans over 50 doubled between 1990 and 2010, according to research from Bowling Green State University. And when researchers interviewed 52 divorced adults for a separate study, 75% cited a lack of commitment as a major reason their marriages ended. Infidelity and constant arguing were also common. Here’s how relationships can deteriorate after years together.1. The Kids Left and the Conversation Went With ThemFor years, there’s always something to discuss when you’re raising kids. Then the last one leaves home, and suddenly you’re having dinner across from someone you haven’t had an actual conversation with in ages. Sociologist Susan Brown told NPR that retirement and an empty nest can leave people wondering, “Is this the person I want to spend another 20 or 30 years with?”2. Then Came the Eye-RollingAfter many years together, some couples have perfected the art of communicating their irritation without saying a word. The sigh when someone starts talking, the sarcastic comments, the eye-rolling. Psychologist John Gottman considers contempt one of the strongest predictors of divorce. Relationship counselor Mig Bennett told Metro that couples stuck in an argument should remember, “You can either be right, or you can be in a relationship.”3. The Marriage Slid Down the Priority ListWith work, raising children, and taking care of aging parents, it’s easy to spend years putting your marriage off until there’s more time. By the time that day comes, you might have forgotten what you used to enjoy doing together. That lack of commitment cited in the divorce study sometimes developed gradually, with couples becoming less willing to work on their relationship.4. Someone CheatedNearly 60% of participants in the 2013 study cited infidelity as a major reason for divorce. Among those who identified a final straw, 24% named cheating. Some people try to repair the relationship afterward, especially when they’ve spent forever raising a family and sharing finances. For others, discovering an affair settles a decision they’ve been struggling with for years.5. Drinking, Gambling and Other Final StrawsSubstance abuse was another reason marriages ended, and the study also identified domestic violence as a common final straw. Addiction can take a serious toll on family finances and relationships, especially when someone refuses treatment. Abuse is a separate and more urgent concern, though, and personal safety comes first. The National Domestic Violence Hotline offers confidential support at 1-800-799-7233.By the time some couples decide to divorce, they’ve spent years getting used to being unhappy together. And after 20 or 30 years of marriage, getting used to something can be a powerful reason to keep doing it.The post 5 Reasons Couples Get Divorced After Decades of Marriage, According to Experts appeared first on vice.