Marriage is a legally recognized union between two people, typically characterized by a commitment to share their lives, responsibilities, and emotional bonds. In the context of marriage, cohabitation, divorce, and remarriage, game dynamics model can be applied to understand how individuals within a society make choices related to forming and dissolving romantic partnerships. Cohabitation involves living together in an unmarried partnership, divorce signifies the legal dissolution of a marriage, and remarriage denotes entering into a new marriage after a previous one has ended. By applying the mean-field game approach, we can gain insights into the dynamics and decision-making processes that underlie these relationship-related phenomena on a broader societal scale. This chapter examines such issues, namely, mean-field games for marriage.