A 2018 study followed married couples over the course of 6 years and found that pornography consumption predicted a higher likelihood of marital separation. Married couples who watched pornography, even once, were more likely to separate over the course of 6 years than those who watched no pornography. Further, the more pornography the couple watched, the more likely marital separation was.
Another 2017 study looked at how attending a religious service regularly and watching pornography affect the quality of the parent-child relationship. Parents who watched pornography displayed an increased frequency of shouting at their children. Parents who both viewed pornography and attended church frequently had the worst communication and relationships with their children of any parents studied. But parents who never viewed pornography and frequently attended church had the best relationships with their children!
Overall, the research is clear. Pornography is harmful for the individual, marriage, parents and children.