Since the latter half of the 20th century, marital and household relationships in the U.S. have become more complex. Important shifts in American family life include a growth in cohabiting couples and greater recognition of same-sex couples. Since 2004, thirty-six states and the District of Columbia have passed laws or issued rulings recognizing same-sex marriage. In this paper, we review four research projects aimed at further enhancing the measurement of same-sex couples. Overall, we found that public reaction to the revised relationship question was muted, and did not result in lower levels of response to either the surveys overall, or the relationship item in particular. Our findings from the largest test, the 2013 American Housing Survey, indicate there is still a high proportion of same-sex married couples whose reports of sex indicate they may be opposite-sex married couples who have marked sex or the same-sex relationship category in error. The administrative linkage projects confirm that there is a serious problem with opposite-sex married couples who misreport sex and artificially inflate the estimates of same-sex married couples. The problem is not as pronounced in the ACS as it was in the 2010 Census, but it is still a serious problem. Our findings show that the measurement of relationships among household members is complex and that we need to continue researching this  topic.