Who is the "enemy" of the main happy marriage

According to a recent study conducted by sociologists in the US, pornography remains the enemy of a happy marriage. The study concluded that married couples watch porn, doubles the chances of divorce. Meanwhile, women watch material with red are 3 times more likely to seek separation. Sociologists at the University of Oklahoma (USA) interviewed many couples married in recent years, to come to this conclusion. According to them, pornography influences happy negatively couples and newlyweds, while no effect on those who are in an unhappy marriage.