In Christensen v. Christensen and Tymczak, 376 N.J. Super. 20 (App. Div. 2005), the court held that a biological father’s obligation to support his children is only subject to being transferred to a step-parent when such party’s actions actively interfere with the children’s support from the natural parent.  In 1985, Plaintiff mother and Defendant Tymczak had a child although the couple never married.  In 1990, the mother and child began living with Defendant Christensen and were married in 1992.  Tymczak paid child support until 1994 when he agreed to an adoption by Christensen. At the last minute, Christensen backed out of the adoption but did not advise Tymczak of such until 2001.  The Appellate Court reversed the trial courts finding which  held support payable by Christensen and noted that a natural parent has the primary duty to provide support if he is able regardless of the conduct of a third party step-parent.  The court stated that the burden remains on the natural father to establish why he should not be required to pay support for his children. 

In Miller v. Miller, 97 N.J. 154 (1984), the court held that in appropriate cases, a stepparent may be obligated to pay child support based on the doctrine of equitable estoppel.  Id. at 167.  The court reasoned that: It is essential...that, in the interim period between the spouse’s separation and the trial court’s decision on permanent child support, the children have a source of support. We therefore find that if, in a motion for pendente lite child support, the natural parent demonstrates that he or she is not receiving support for the children from their other natural parent and establishes by affidavit that the stepparent’s conduct actively interfered with the children’s support by their natural parent, so that pendente lite support may not be obtained from the natural parent, the children should be awarded pendente lite support from the stepparent. By permitting a spouse to get interim support for the children, we alleviate any immediate hardship to the children caused by the breakup of a marriage in which a stepparent is the sole or major source of support for the family.  Such interim support order should remain in force until circumstances justify a modification of the Order or the court makes its final determination.

Person, other than child's natural or adoptive parent, may be charged with a parent's duties and responsibilities if he or she stands in loco parentis.  Cumberland County Bd. Of Social Services v. W.J.P., 333 N.J.Super. 362 (2000).  Once natural parent has been identified, has been ordered to pay child support, and establishes relationship with minor, in loco parentis support cannot be compelled from stepfather.  Id.