‘Marriage, civil partnership, and cohabitation’ examines the changes that have recently taken place in the composition and nature of the family unit and asks: what is a family? Over recent decades, the definition has broadened and the word family has come to have greater significance. What is marriage? There is no single correct definition. The law needs to be clear that it is seeking to define a legal understanding of marriage. Perhaps we need a ‘sexless family law’: one where the central focus of the law is not on sexual relationship, but the care given within that relationship.