Lisa conceived a third son, Dane, during a separation from her husband, Guy. Dane was born six months after their divorce. Guy continued to support all three sons, and cared for Dane when he cared for his other sons. Phillip, Dane’s biological father, filed a petition to declare paternity of Dane, requesting joint custody. Lisa’s motion to quash the petition was denied. She filed a petition for writ of mandate challenging the denial. In this opinion, the appellate court granted her petition. Phillip had no standing to file the action under Family Code section 7630 because he was not a presumed father. Further, he had no protected liberty interest which overcomes the Family Code standing and presumption statutes. Only biological fathers who have an existing relationship with the minor have a protected liberty interest. Here, Guy was the only father Dane had ever known. There was no compelling reason under these circumstances to invalidate the application of the Family Code.