During the period of cohabitation, if one party is in debt in its own name, whether the other party should bear joint and several liability for repayment depends on whether the creditor can prove that the debt purpose of the debtor is the production and living needs of both parties.
 First, the legal nature of cohabitation is different from marriage. The cohabitation relationship includes the broad and narrow sense, and the narrow sense, that is, the social relationship formed by the public cohabitation of husband and wife or secret sexual relationship between men and women without marriage registration. Although cohabitation relationship and marriage relationship have similar characteristics, they do not fully possess the constituent elements of marriage relationship. On the one hand, cohabiting men and women who have not gone through marriage registration do not necessarily meet the substantive requirements of marriage, while men and women in the marriage relationship have gone through marriage registration, which generally meets the substantive requirements of marriage. On the other hand, the personal relationship and property relationship occurred during the cohabitation of men and women are treated as general personal relationship and property relationship, which are not subject to the marriage law, while the personal and property disputes generated by the husband and wife during the existence of the marriage relationship are subject to the adjustment of the marriage law.