Understanding Thirds: Protecting Your Relationship When Outside Forces Threaten Your Bond
You’re in love. You’ve found your person. You’ve made that spoken or unspoken pact to choose each other every day, no matter what storms roll through.
But then someone—or something—shows up.
An old flame. A demanding job. A best friend who never warmed up to your partner. Suddenly, it’s not just the two of you anymore.
There’s a third.
What Is a “Third”?
Let’s be clear: thirds are inevitable.
A third (also called an outsider or intruder) is anyone or anything that draws attention, energy, or loyalty away from the relationship in ways that create emotional disruption or threat.
They can be obvious or sneaky. Human or not. A third could be:
· A family member
· A friend
· A pet
· A job
· A phone
· A fantasy
· A secret
· Even an old identity or unexamined loyalty to your past
"You Might Be Dealing with a Third If..."
· You vent to your best friend about your partner—but avoid talking directly to your partner.
· Your phone gets more eye contact than your spouse at the end of the day.
· You share emotional highs (or selfies) with your ex before your partner.
· Your dog sleeps in your bed, but your partner doesn’t feel welcome there.
· You delay major decisions until you “run them by your mom.”
· Your job texts or emails after hours and you always respond—mid-conversation.
· You spend hours in fantasy (shows, books, porn, daydreams) that feel safer than intimacy.
Thirds aren’t always dramatic. Often, they’re subtle—and sometimes even well-intentioned. But over time, these moments erode trust, intimacy, and the sense that “we’re each other’s safe place, and in each other’s care.” The problem arises when they go unexamined, when they come before the relationship, or when they aren’t managed mutually.
Left unchecked, thirds create a leak in the boat. And if you shoot a hole in the boat, you both go down.
When Thirds Hijack the Connection
Scenario 1: The Ex Who Never Fully Left
A partner stays emotionally entangled with an ex. “She’s just a friend. You should just trust me,” he says—while bristling at the idea of introducing his current partner or making the friendship transparent. He keeps the connection alive, private, and protected – while his partner spirals, feeling excluded and unseen. Angrily he unilaterally ends it with the ex to stop the fighting.
- The real hurt?
Not the history. It’s the secrecy and exclusion.
It’s the wall—the implicit message: “This part of me isn’t for you, and I’ll protect it from you—not for you.”
The ex’s comfort was prioritized over the current partner’s inclusion.
👉 His partner got compliance—"I’ll keep the peace”—not alliance—"I’ve got your back.”
A better message:
“I don’t do relationships that exclude my partner.”
✅ Win/Win Alternative:
Agree to a friendship policy where ongoing connections with others are fully transparent, inclusive, and open to renegotiation if one partner feels threatened.
Scenario 2: The Interfering Parent
A father-in-law critiques the couple’s decisions, makes sideways comments, and refuses genuine connection with his child’s partner. Instead of setting boundaries, the adult child defends or minimizes the father’s behavior, leaving their partner to navigate the discomfort alone.
-The real hurt?
Not the closeness with a parent. It’s the lack of protection.
It’s the wall—the implicit message: “You’re on your own with my family.”
Family harmony was prioritized over the partner’s emotional safety.
👉 Their partner got appeasement—“Let’s not rock the boat”—not protection—“I’ll draw the line.”
A better message:
“My loyalty is with you, and you are not the outsider. ‘We’ are in the insiders, if someone mistreats you, they’re mistreating us.”
✅ Win/Win Alternative:
Together, the couple agrees on limits for parental involvement—and backs each other up, even if it means difficult conversations with family.
Scenario 3: The Consuming Hobby
One partner has a passion—say, long-distance cycling that takes up huge amounts of time, energy, and becomes a partner’s main emotional outlet. It’s their stress-reliever, their friend group, their identity. Meanwhile, their partner is left to handle life and connection on their own.
-The real hurt?
Not the passion or independence. It’s the emotional absence.
It’s the wall—the message: “My best self exists away from you.”
Personal freedom was prioritized over protection of the relationship.
👉 They got tolerance—"You’ll just have to deal with this”—not inclusion—"Let’s make this work for both of us.”
A better message:
“I want to love this hobby and still include you in my world.”
✅ Win/Win Alternative:
Work out a shared schedule that honors individual fulfillment and protects quality time as a couple. Explore how the hobby can be shared or how its time investment can be balanced with the relationship’s needs.
The Real Issue: It’s Not the Ex, the In-Law, or Hobby. It’s the Wall.
It’s the failure to integrate your partner into important parts of your life. It’s treating your partner as optional where they should be central. That’s the real hurt.
Emotional energy, attention, vulnerability—these aren’t neutral commodities. When given outside the relationship without mutual consent or boundaries, they dilute the intimacy that should be sacred.
The Couple Bubble: Your Shared Sacred Space
Couples in distress often believe conflict is the problem, but in truth, many conflicts are symptoms of a deeper issue: the failure to protect the couple bubble.
The couple bubble—a concept from Dr. Stan Tatkin’s Psychobiological Approach to Couple Therapy (PACT)—is the mutually constructed, co-regulated space between two people that acts as their relational safety net. It’s an agreement to put each other first, to shield one another from threats (including third parties), and to operate as a team – even under pressure.
Protection isn’t just physical – it’s emotional, psychological, social, relational, and even digital. It means shielding your partner not just from harm, but from secrecy, exclusion, ridicule, or confusion.
Couples who thrive are the ones who adopt a simple, high-integrity code of conduct:
“If it is not good for you then it is not good for me…and vice versa.” Good for both is the goal – because in secure-functioning relationships, love isn’t measured by proximity alone—it’s measured by mutual protection, sensitivity, and fairness – and ultimately having agreements in place that create win/wins.
In secure-functioning relationships, the “win” is not personal victory. It’s mutual benefit. It’s asking: what decision strengthens our bond, protects our bubble, and keeps us aligned as a team—even if it’s uncomfortable in the short term? And this doesn’t mean sameness. It means mutual benefit. Decisions are made not for personal comfort, but for shared security and relational strength.
Cleaning Up the Mismanagement of Thirds
✅ Create an Agreement Together
Talk explicitly about what counts as a third. Define your values. Make your couple bubble a conscious commitment.
✅ Manage Thirds Together
If a third enters your shared life, manage it as a team. Outsiders shouldn’t be negotiated solo.
✅ Ask the Ultimate Test Question:
“Can I advocate for this—on behalf of my partner?”
If the answer is no, you’re prioritizing comfort over connection.
A Modern Love Creed: “If You’re Not Pro-Us, You’re Not For Us”
This isn’t about cutting people off. It’s about protecting what’s sacred.
· If someone doesn’t actively support the partnership, they don’t get intimate access.
· If they won’t respect the couple system, they’re not safe to keep close.
· If something causes repeated distress—even if it seems small—it matters. And you listen.
Final Thought: Secure-Functioning Is a Practice, Not Perfection
You don’t need to be perfect to protect your bond.
You need to be aware, willing, and in alignment.
Secure-functioning couples don’t avoid conflict—they’re just proactive, transparent, and aligned. They work like synchronized swimmers: different bodies, one rhythm.
✅ A win/win might look like:
· Ex situation: Ending contact with an ex—not out of pressure, but out of shared clarity that the relationship comes first.
· Family situation: Setting kind but firm boundaries with family—and showing up for your partner publicly and privately.
· Hobby situation: Creating a shared calendar where both passion and partnership get space to breathe.
“Relationships don’t fall apart from outside forces—they fracture from within when we fail to protect each other. But the power to repair, reconnect, and rewrite the rules is always within reach. You don’t have to be perfect—just committed. The strongest bonds aren’t free from thirds… they’re forged by how two people choose each other again and again, no matter what tries to come between.