Blended Families: When The Conduct of a Stepparent Creates Obligation

BLENDED FAMILIES: WHEN THE CONDUCT OF A STEPPARENT CREATES OBLIGATION

For many years, the law has been criticised for lagging behind the lived realities of modern society. Family structures have evolved significantly, yet the law has often remained rooted in traditional notions of the nuclear family. Increasingly, however, South African courts appear willing to acknowledge that families do not always fit neatly into conventional categories.

One area where this evolution is becoming particularly apparent is in matters involving blended families, as increasingly diverse family structures give rise to complex legal questions that courts are being called upon to grapple with and resolve. One such question is whether a stepparent who has assumed a parental role in a child’s life can later disavow any responsibility for that child following the breakdown of the relationship with the child’s biological parent.

Recent case law suggests that, in appropriate circumstances, a stepparent who has voluntarily assumed the role of a parent may not be entitled to simply walk away from the obligations that accompany that role. Importantly, however, these decisions do not establish an automatic duty of support on the part of stepparents. As with most areas of law, the outcome remains highly fact-specific and dependent on the particular circumstances of each case.

NM v BM and Others: The Foundation of the Modern Approach

The starting point for any discussion on stepparent maintenance obligations is NM v BM and Others (11384/2024) [2024] ZAWCHC 254 (11 September 2024). The matter arose as a Rule 43 application, where the court was required to consider whether a stepparent could be held liable for the maintenance of his stepchildren following the breakdown of the marriage.

The court acknowledged the common law position that a stepparent does not automatically owe a duty of support to a stepchild. However, this was not the end of the enquiry. Rather than adopting a rigid legalistic approach, the court undertook a nuanced and child-centred analysis. Central to its reasoning was the constitutional imperative that the best interests of the child are of paramount importance in every matter concerning children. The court considered whether the respondent had assumed the role of in loco parentis, effectively stepping into the position of a parent. In doing so, it examined the practical realities of the family unit and the role the respondent had played in the children’s lives.

Particularly significant was the fact that the respondent had provided a family home for the children, treated them as his own, and presented himself to both the family and the wider community as a parent figure responsible for their care and upbringing. His active involvement in their lives created expectations and dependencies that could not simply be ignored once the marital relationship ended.

The court held that section 28(1)(b) of the Constitution extends beyond purely biological or legally adopted parent-child relationships and may encompass stepparents who have voluntarily assumed parental responsibilities. Having assumed the role of in loco parentis, the respondent could not simply withdraw from that role at will and evade the responsibilities that accompanied it.

The judgment is significant not because it creates a blanket rule that all stepparents owe maintenance obligations, but because it recognises that parental responsibility may arise from conduct and assumption of responsibility, rather than biological ties alone. The implications of the judgment are nuanced. On the one hand, some may argue that it could make stepparents more cautious about the extent to which they involve themselves in the upbringing of their stepchildren if doing so may attract continuing obligations after the relationship ends. On the other hand, the judgment provides reassurance to blended families by demonstrating that courts are prepared to look beyond formal legal relationships and consider the reality of family life. Most importantly, the judgment signals a willingness by the courts to recognise modern family dynamics while prioritising the welfare of children affected by the dissolution of those family structures.

CMN v NN: Drawing the Line Where No Undertaking Exists

The principles articulated in NM v BM were subsequently considered in CMN v NN (2025/177451) [2026] ZAGPJHC 320 (31 March 2026).

In this matter, the husband sought interim maintenance in Rule 43 proceedings. He was unemployed, resided in the matrimonial home and the wife was covering certain of his living expenses, including his food costs. As part of his claim, he sought a cash component of maintenance in respect of a child conceived during an extramarital affair and born outside the marriage, which affair the wife cited as one of the reasons for the breakdown of the marriage when instituting divorce proceedings. He also sought a contribution towards transport costs for himself and the child, together with shared control of the rental income derived from the joint estate. The husband was effectively asking the wife to contribute towards the maintenance of the child and thereby assist him in complying with his own maintenance obligations towards the child. The court was therefore required to consider whether the wife bore any obligation to support a child who was neither biologically related to her nor connected to the marriage in any meaningful sense.

The court acknowledged the established legal principle that a person married to a child’s biological parent does not acquire a duty to support that child merely by virtue of the marriage, unless they have undertaken such obligations. In considering the issue, the court relied on NM v BM and reaffirmed that the threshold inquiry is whether there has been an undertaking of support and an assumption of parental responsibility sufficient to establish an in loco parentis relationship. The court emphasised that the assumption of such responsibilities remains a high threshold, it must be express an unambiguous. On the facts before it, the court found no evidence that the wife had ever undertaken responsibility for the child. The child was effectively a stranger to the marriage and there was no indication that she had assumed any parental role whatsoever. Accordingly, the husband’s claim for a maintenance contribution in respect of the child was dismissed. The court was further unwilling to make an order directing the wife to share the rental income with the wife as it fell outside the scope of the intended purpose of the Rule 43 proceedings and the matter was left for the trial court.

The significance of CMN v NN lies in what it confirms: NM v BM does not establish an open-ended duty of support. Rather, liability depends on evidence that the person concerned voluntarily assumed parental responsibilities and created a relationship that justifies the imposition of continuing obligations.

SZM v MNM: The Importance of Evidence

The third judgment, SZM v MNM (127136/2024) [2025] ZAGPPHC 614 (11 June 2025), further illustrates the fact-sensitive nature of these disputes.

In this Rule 43 application, the applicant sought interim relief relating to spousal maintenance, child maintenance, care and contact arrangements, guardianship issues, and a contribution towards legal costs. Of the three children involved, only one had been born of the marriage.

The central dispute was whether the parties had created a blended family structure in which the respondent had assumed parental responsibilities towards the applicant’s two children from a previous relationship. To establish this, the applicant relied on WhatsApp correspondence which, she argued, demonstrated that the respondent had assumed the role of in loco parentis. She also produced one month’s evidence of a school fee payment made by the respondent for one of the minor children and alleged that he also paid the two minor children’s school fees monthly. However, the financial records were inconsistent and did not substantiate a pattern of regular payments, and the applicant also failed to adequately explain or substantiate the calculation of the cash contribution claimed in respect of the minor children.

Further, the court noted that there was little evidence regarding the social, emotional and psychological bonds between the respondent and the children to conclusively establish the nature and extent of the relationship. The Family Advocate’s report before the court dealt only with the child born of the marriage and did not address the relationship between the respondent and the applicant’s other children. As a result, the court found that it lacked sufficient information to determine whether the respondent had indeed assumed the role of in loco parentis.

In discussing NM v BM, the court recognised that the earlier judgment had highlighted the complex realities of stepparent maintenance and challenged traditional understandings of parental responsibilities and rights. It acknowledged the need to consider the lived realities of modern family life, including blended and customary family structures, when interpreting parental care obligations under section 28(1)(b) of the Constitution and section 18 of the Children’s Act. However, the court emphasised that each matter must ultimately be decided on its own facts. Unlike NM v BM, there was insufficient evidence before the court to establish the existence of the necessary social and emotional bonds or to conclude that the respondent had agreed to assume parental responsibilities for the children. The court therefore left the question of whether the respondent had assumed liability to maintain the children for determination at trial.

A Developing Area of Family Law

Taken together, these three decisions reveal an emerging judicial willingness to engage with the realities of modern family structures rather than relying solely on traditional legal categories. What emerges is neither a radical departure from established principles nor an automatic extension of maintenance obligations to all stepparents. Rather, the courts appear to be adopting a more flexible, child-centred approach that recognises the complexities of contemporary family life while remaining grounded in the specific facts of each case.

For blended families, these judgments provide an important reminder that family law is increasingly concerned with the substance of parental relationships rather than merely their form. The question is no longer simply who a child’s legal or biological parent is, but also who has chosen to act as one.