Michelle W. v. Ronald W

In Michelle W. v. Ronald W. (1985) 39 Cal. 3d 354, the child was conceived while the mother was living with her husband but having an affair with another man, Donald. The husband and wife raised the child together for four years, until they ended the marriage, after which time the husband continued his parental relationship with the child. The mother subsequently married Donald and they sought to establish his paternity. Michelle W. upheld application of the section 7540 presumption in favor of the husband, and denial of a motion for blood tests, because the husband's interest in continuing his established relationship with the child and state's interest in "familial stability and the welfare of the child" outweighed Donald's private interest in establishing paternity and the child's interest in a legal determination of her biological parentage. (Michelle W., at p. 363.)