Sociological: Couples who cohabit are least likely to marry each other, are likely to have a fleeting romance rather than a lasting relationship, have a relationship that tends to "kill" romance, often have a "marriage of convenience" rather than marriage of commitment, have no lasting commitments or responsibilities, do NOT have specialization of responsibilities, miss something in maturing process, avoid dealing with some of joint decisions that married couples must make, have more difficulty resolving conflicts, often lack a common purpose, often have different intentions for the future, have less support and benefits, often lay a foundation of distrust and lack of respect, do NOT experience the best sex, often face parental disapproval, hurt their children