How to Set Boundaries with Exes about Co-Parenting in a Blended Family

Wednesday, February 19, 2025.

Blended families are an intricate dance of schedules, emotions, and the occasional "Why did your ex just text you at 10 p.m.?" moment.

If co-parenting with an ex wasn’t already a challenge, balancing those dynamics within a new marriage or partnership can feel like playing relationship Jenga—one wrong move and everything topples.

So, how do you set boundaries with an ex while maintaining a peaceful co-parenting relationship?

Is it possible to keep the family functional without alienating your new partner or causing unnecessary conflict?

The short answer: Yes.

The longer answer involves a deep dive into family psychology, boundary-setting strategies, and a look at both confirming and contradictory research on blended family success.

Why Boundaries with Exes Matter in a Blended Family

Boundaries in blended families aren’t just about preventing drama—they’re about fostering emotional security for everyone involved, including the children.

Studies show that children in blended families thrive when they experience consistency, stability, and minimal interparental conflict (Jensen & Harris, 2017).

However, conflicting research suggests that overly rigid boundaries can create unnecessary distance between co-parents, increasing stress and negatively impacting child adjustment (Ganong & Coleman, 2017). The key is striking a balance between open communication and firm, respectful boundaries.

Identifying Your Boundary Style

Not all families approach co-parenting the same way.

Research suggests that blended families tend to fall into one of three co-parenting styles (Ahrons, 2004):

• Cooperative Co-Parenting: Frequent, respectful communication with clear but flexible boundaries. Best for child stability but requires emotional maturity from all parties.

• Parallel Co-Parenting: Minimal communication, strict division of parenting responsibilities, and limited flexibility. Reduces conflict but can make coordinating major decisions difficult.

• Conflicted Co-Parenting: High levels of unresolved tension, poor communication, and boundary violations. Most damaging for children’s long-term well-being.

Knowing where you and your partner fall within these styles can help determine the type of boundaries that will work best for your family.

Establishing Healthy Boundaries Without Fueling Conflict

Define What’s Appropriate Communication

Your ex isn’t your emotional confidant anymore.

While some casual communication is natural, emotional boundary violations—such as venting about personal struggles or discussing relationship issues—blur the lines and can create tension in your new marriage.

• Healthy boundary: “We will only communicate about our children, logistics, and necessary co-parenting issues.”

• Unhealthy boundary: “We still text daily about our lives because we are ‘best friends’ even though we are divorced.”

Numerous research studies indicate that co-parents who maintain a clear communication focus on their children experience fewer conflicts (Hetherington & Kelly, 2002).

However, some studies suggest that maintaining a friendly relationship with an ex can sometimes reduce stress—but only if both parties and their new partners are comfortable with it (Afifi & Schrodt, 2003).

Set Physical Boundaries Around Home and Personal Space

Having an open-door policy for an ex to walk in at any time might seem harmless at first—until it starts creating tension in your new relationship.

• Healthy boundary: “Pick-ups and drop-offs happen outside or at a neutral location.”

• Unhealthy boundary: “My ex still has a key to the house because it’s more convenient.”

Studies show that clear spatial boundaries reduce conflict and provide a sense of security for all parties involved (Ganong & Coleman, 2017).

Conversely, allowing blurred lines—such as exes coming into the home unannounced—can lead to resentment in new partnerships (Stewart, 2007).

Clarify Financial Boundaries

Money is one of the biggest sources of conflict in both co-parenting and blended families. Who pays for what? Where do the financial responsibilities begin and end?

• Healthy boundary: “We will share child-related expenses based on an agreed-upon plan, and any additional financial favors should be discussed with all parties.”

• Unhealthy boundary: “My ex still borrows money from me because I feel guilty.”

Confirming research shows that financial ambiguity in blended families can create unnecessary stress and lead to power struggles (Sweeney, 2010).

Meanwhile, some studies suggest that exes who remain financially interdependent may create a sense of extended family cohesion—but only if both partners in the new relationship agree (Jensen & Lippold, 2018). Obviously, YMMV.

Protect Your Current Relationship

New relationships require emotional priority to thrive. If an ex is consuming an unreasonable amount of time, energy, or emotional space, it can create unnecessary friction.

• Healthy boundary: “We will discuss co-parenting issues in a structured way, without allowing them to overshadow our own relationship.”

• Unhealthy boundary: “My ex and I talk multiple times a day, and my current partner just has to deal with it.”

Research shows that partners in blended families report higher relationship satisfaction when they feel like a priorityrather than an afterthought (Cartwright, 2010). However, overly strict boundaries—such as forbidding any non-essential communication—can increase stress rather than alleviate it (Sweeney, 2010).

Communicating Boundaries Without Creating Resentment

Even the best boundaries won’t work if they aren’t communicated properly.

• Use “I” statements. Instead of “You need to stop texting your ex so much,” try: “I feel uncomfortable when there is frequent personal communication with your ex, and I would appreciate clearer boundaries.”

• Keep it child-focused. If your ex questions a boundary, frame it around what’s best for the kids: “I think structured communication helps the kids feel more secure.”

• Be consistent. Changing the rules depending on emotions or convenience leads to confusion and conflict.

Final Thoughts: Boundaries Keep Families Functional, Not Fractured

Setting boundaries with an ex in a blended family isn’t about control—it’s about creating a structured environment where all relationships can thrive.

The best boundaries strike a balance between respectful co-parenting and protecting the emotional integrity of your new relationship.

Remember: Healthy co-parenting isn’t about perfection, it’s about stability. If all parties are on the same page, boundaries won’t feel like restrictions—they’ll feel like the framework that holds everything together.

Be Well, Stay Kind, and Godspeed.

REFERENCES:

Ahrons, C. R. (2004). We're still family: What grown children have to say about their parents' divorce.HarperCollins.

Afifi, T. D., & Schrodt, P. (2003). Communication processes that promote resilience in post-divorce families. Human Communication Research, 29(2), 148-178.

Cartwright, C. (2010). Blended families: Changes and challenges. Journal of Divorce & Remarriage, 51(8), 507-525.

Ganong, L. H., & Coleman, M. (2017). The role of boundary ambiguity in stepfamily stress. Journal of Family Theory & Review, 9(3), 287-304.

Hetherington, E. M., & Kelly, J. (2002). For better or for worse: Divorce reconsidered. W. W. Norton & Company.

Jensen, T. M., & Harris, K. M. (2017). Stepfamily relationship quality and children’s well-being: A longitudinal analysis. Journal of Marriage and Family, 79(3), 762-778.

Sweeney, M. M. (2010). Remarriage and stepfamilies: Strategic sites for family scholarship in the 21st century. Journal of Marriage and Family, 72(3), 667-684.