The Hidden Strain in Stepfamily Dynamics: When a Biological Parent Triangulates by Ignoring or Excluding the Stepparent
- Robin
- Apr 25
- 10 min read
Blended families are complex. With multiple adults involved in a child's life, navigating relationships can be tricky. One of the more subtle and emotionally charged dynamics that can arise is when a biological parent excludes, ignores or tries to limit the role of the stepparent—whether deliberately or unintentionally. This form of triangulation often leaves the stepparent feeling isolated, disrespected, and confused about their role within the family structure.
Triangulation can align with relational aggression and cause additional stress, conflict and complications in the two-home structure. This frustrating and damaging dynamic often occurs between the specific role of the biological mom and the stepmom. Experiences that stepmoms often speak about is being left out of conversations where they are the topic, not being recgonized for their role as a parent, various attempts to be exluded from meaningful moments of the child's life, and perhaps the most harmful: a bilogical parent seeking to limit or damage the relationship that a stepparent has with their stepchild.
In this blog post, we’ll explore the intersection of triangulation and relational aggression and what that looks like in the context of a biological parent excluding the stepparent, why it happens, and the emotional impact it can have on everyone involved. Most importantly, we’ll discuss how to navigate these tricky situations with clear boundaries, respectful communication, and an emphasis on the child’s well-being!
What is Relational Aggression
Relational aggression in family systems is the use of indirect, emotionally manipulative behaviours by one family member to damage another’s relationships, social standing within the family, or sense of belonging. It often involves subtle tactics like exclusion, gossip, triangulation, or emotional withholding, rather than direct confrontation.
What Is Triangulation?
In family systems, triangulation occurs when a third party is pulled into an emotional conflict or issues between two people, often against their will or without their awareness. In this case, it’s when the biological parent creates a situation where the stepparent is excluded or ignored, either through actions or words, while they continue to communicate directly with the other biological parent only.
Triangulation disrupts healthy communication and creates emotional distance or tension between family members. It’s especially harmful in the stepparent-child relationship, as it undermines the stepparent’s sense of belonging and authority within the family unit.
Relational Aggression + Triangulation = A Powerful Emotional Undercurrent
When relational aggression (indirect social harm) combines with triangulation by exclusion, the result is a subtle yet powerful way to control dynamics, preserve loyalty, and undermine the stepmom’s role—without confrontation.
Triangulation in the form of exclusion can take on many shapes, often going unnoticed until the emotional effects become too great to ignore. Choosing not to involve the stepparent may be appropriate if the relationship is fairly new or if the stepparent is highly confrontational. However, there are circumstances where it may be more suitable (than not) to include the stepparent. These situations include:
If the stepparent has been present in the child's life for a period of time
If the stepparent is showing up as a parent in the child's life (school pickups, taking on care of the child, etc.)
If the other home has requested the inclusion of the stepparent
If the stepparent has vocalized their desire or interest in being involved
Here are a few common scenarios where Triangulation and Relational Aggression can exist in the Stepparent world:
Excluding the Stepparent from Parenting Decisions
The biological parent makes major decisions, like school choices or medical appointments, without including the stepparent in the conversation—even though they are actively involved in those areas. This might include scheduling important events or making decisions about discipline without consulting the stepparent or informing them of the details.
Relational aggression: The exclusion sends a message that the stepmom isn’t “real” family or worthy of involvement.
Triangulation: The bio mom uses the dad as a gatekeeper, keeping the stepmom out of the parenting loop.
2. Leaving the Stepparent Out of Conversations
Whether it’s via text, phone calls, or in-person exchanges, the biological parent might directly communicate only with the other biological parent, excluding or ignoring the stepparent—even when the stepparent is responsible for a large part of the child’s day-to-day care. Choosing to only communicate with the biological parent even though the discussion includes or impacts the stepparent is a purposeful choice to exclude the stepparent.
Relational aggression: The biological speaks ABOUT the stepparent and concerns ONLY to the biological parent and not directly to the stepparent
Triangulation: creates a closed loop where the stepparent is left out of critical conversations. This sends a message to the child that the stepparent isn't part of the parenting dynamic. This also limits the stepparents ability to resolve conflict.
3. Disregarding the Stepparent’s Role in Family Events
Another form of triangulation is when the biological parent disregards the stepparent during family gatherings, extracurricular activities, or celebrations. This can happen subtly, like leaving out the stepparent from planning or decisions, or it could involve actively excluding them from being a part of the child's life events by requesting or implying that a stepparent doesn't attend.
Relational aggression: The biological suggests that only biological parents attend a birthday party, christmas concert, recital, etc., despite the family role that the stepparent holds in their home
Triangulation: The child feels pulled between wanting the stepparent there and the loyalty to their biological parents feelings about not wanting the stepparent to attend.
4. Withholding Information from the Stepparent
Sometimes the biological parent might keep important information from the stepparent—whether about the child’s health, school updates, or emotional state. This creates confusion for the stepparent, who may find themselves navigating parenting duties without all the necessary information.
Relational aggression: This is a power move, showing control and keeping the stepmom in a reactive position.
Triangulation: The child or dad is left to relay information, putting them in the middle and creating emotional tension.
5. Social Undermining
The bio mom might talk negatively about the stepmom to the child, friends, or even extended family—subtly discrediting her role without being overtly “hostile.” They may comfortably sit in situations where others are negatively talking about the stepparent around the child, thereby looking like they aren't participating but still sending a message that the behaviour is acceptable. They may use personal or private information against the stepparent to bolster their own relationship with others.
Relational aggression: Damaging reputation through gossip, sarcasm, or minimizing the stepmom’s contribution.
Triangulation: Turning others into allies, drawing loyalty away from the stepmom, and isolating her socially.
Why Does Triangulation Happen?
There are several reasons why a biological parent might unintentionally or even intentionally triangulate the stepparent by ignoring or leaving them out. It’s often rooted in a combination of emotional, relational, and logistical factors:
Lingering Tension
Sometimes, the biological parent may still experience unresolved hurt from their past relationship. There may be an unresolved conflict between the biological parents. In these circumstances, the biological parent may consciously or subconsciously choose to transfer their negative feelings onto the stepparent.
Lack of Boundaries in the Co-Parenting Dynamic
If the co-parenting relationship lacks clear boundaries and roles, it’s easy for communication to become blurred. The biological parent may not see the need to involve the stepparent in certain decisions, especially if she feels the other biological parent should be primarily responsible.
Perceived Role of the Stepparent
The biological parent might not fully recognize or respect the stepparent's role, especially in the early stages of blending families. They might view the stepparent as "just" an extension of their partner, not an active participant in parenting. This can be exacerbated if they still see themself as the primary caregiver or decision-maker for the child.
Emotional Distance or Discomfort
In some cases, a biological parent may feel uncomfortable with the stepparent’s involvement, either because of personal insecurities or fear of overstepping boundaries. They may unintentionally keep the stepparent out to preserve what she perceives as the “core family” structure.
Reflection of Their Family Structure
Some biological parents go on to build complex blended families within their own homes and develop strategies that don't align with the other home. For example, some families blend and work together as one family structure. Others remain separate families under one roof. The expectation that the boundaries within their home will apply to others can increase conflict.
Seeking a Sense of Control
In the most limiting scenario, a biological parent may be looking to control the relationship of others. Some biological parents struggle to accept the reality of divorce, a two-home structure and the relationships that a child is fostering in another home. Triangulation is their way of trying to limit and undermine the relationship that their child has with another parent.
A lack of Emotional Maturity
A biological parent may not struggle with emotional boundaries. They may not be able to understand where they are and where others begin and therefore the stepparent role may be seen as a threat. The emotional reaction may come out as triangulation in an attempt to reassert their emotional authority.
Retaliation
Retaliation can be a major driver behind why some biological triangulate and exclude stepparents. In many cases, the behaviour isn’t just about insecurity or immaturity—it’s also about getting even, restoring power, or expressing unspoken hurt or anger. And because confrontation may feel too risky (or socially unacceptable), relational aggression and triangulation become the tools of choice
Regardless of why triangulation happens, it can be frustrating, emotionally scary, and difficult to deal with.
The Impact of Triangulation on Stepparents
Exclusion or triangulation can have a significant emotional toll on the stepparent. Here are some of the key impacts:
Undermined Authority and Respect
Stepparents may feel disrespected and undermined in their role. When they are excluded from decisions or left out of important discussions, it becomes harder to establish authority or credibility with the child.
Isolation and Confusion
Being left out can lead to feelings of isolation, as the stepparent might not know where they fit in the family dynamic. This can also create confusion about their role—are they truly part of the team, or just a secondary figure?
Strained Relationship with the Biological Partner
The exclusion may cause friction between the stepparent and the biological parent (usually the partner). If the biological parent's behaviour goes unaddressed, the stepparent may feel unsupported or ignored by their partner, leading to resentment or emotional distance within the partnership.
The Impact of Stepmom Triangulation on Stepkids
Creates Loyalty Conflicts for the Kids
Kids are highly attuned to their bio mom’s emotional cues. If the bio mom is publicly inclusive but privately critical or emotionally withholding toward the stepmom, the kids pick up on that:
They may feel torn: “Mom says she’s okay, but says really negative things?”
They may test or sabotage the bond with the stepmom to stay loyal to Mom.
They may be friendly in private but cold or conflicted in front of their mother.
So the relationship becomes inconsistent—warm one day, distant the next.
2. Undermines the Stepmom’s Authority
If the bio mom "includes" the stepmom but doesn't reinforce her authority (or worse, subtly dismisses it), the stepkids get mixed messages:
“You have to listen to her... but not really.”
“She’s there to help, but she doesn’t make the rules.”
This weakens the stepmom’s ability to set boundaries, follow through, or build mutual respect. She’s caught in a lose-lose: too involved to be “just a friend,” and not empowered enough to be a true parent.
3. Breeds Emotional Exhaustion
The stepmom often ends up overfunctioning—trying to prove her worth, avoid stepping on toes, keep the peace, and win over the kids. However because her inclusion is conditional, she rarely feels safe or grounded in the role. That emotional labour builds up—and can lead to burnout or detachment.
4. Builds Silent Resentments
If the stepmom senses that her role is performative or unstable, resentment can quietly grow— toward the bio mom, the partner, and sometimes even the kids. And when that resentment leaks out (even subtly), kids notice. It can erode trust or connection.
What Can Be Done to Prevent These Complicated Dynamics?
Here are a few strategies to help both parents create a healthier, more inclusive dynamic:
Recognize these Patterns
Naming these behaviours can help to diffuse their power. It can be difficult early on to understand what is happening. If can be a lingering feeling that you have never felt that needs some unpacking. Talk to a professional and work through the undercurrents of what is happening and how you are feeling. A therapist that has knowledge of two home structures can be very helpful in helping to identify patterns that can exist in these complicated scenarios.
Clear, Respectful Communication
Both parents (biological and stepparent) need to maintain open, respectful communication. Have intentional conversations early on if things don't feel ok. Use group text messages to send information so that all parents are included. They can individually choose to opt out but the offer for communication is there. There are also parenting apps (like the family wizzard) for parents of high conflict or parents who prefer a more structured platform.
Set Boundaries and Expectations Early On
Establishing clear expectations around roles and responsibilities—between the biological parents and the stepparent—helps ensure everyone understands their place and responsibility. This can reduce miscommunication and prevent feelings of exclusion. Your partner must advocate for inclusion. Couples counselling can be a great platform for working through intentional conversations surrounding the expectations of the stepparent role and can help define what structure you want within your home.
Create an Inclusive Parenting Plan
Develop a parenting plan that includes everyone’s input, which helps everyone (biological and stepparent) know where they stand. Include the stepparent in any major parenting decisions and keep them informed about any changes in the child’s schedule or needs.
Work Together as a Team
The biological parents and stepparents should view themselves as a team. This means respecting each other’s role in the child’s life and working together to make decisions in the child’s best interest. When issues arise, deal with them directly and respectfully without involving the child.
Empower your Role
The Stepparent role is special, unique and important. Your role matters and you don't need validation from anyone outside of your home. Focus on the relationships that value you, continue to build a strong partnership with your spouse and invest in tools to help with conflict (like therapy, a support group, podcasts, etc.)
Conclusion
Excluding the stepparent or leaving them out of parenting decisions and communication can create unnecessary tension and emotional strain within a blended family, especially when a stepparent is willing and able to be a participating member. Recognizing the signs of triangulation, setting clear boundaries, and maintaining open lines of communication can help ensure a more inclusive, supportive environment for everyone involved.
An ideal goal would be to create a cohesive, collaborative family unit that supports the child’s emotional well-being, however not everyone is consistently working towards that goal at all times and that reality can be devestating. By respecting everyone’s role and ensuring that all voices are heard, stepparents can feel valued and included—and the entire family can thrive.
If you're struggling with family dynamics, we offer therapy and resources to help you manage the challenges of blended family life. You are not in this alone and you don't need to suffer in silence or think that these behaviours are ok. Reach out today and start building tools for resileince and coping!
