AITA for Telling My Sister I Don’t Know if I Love Her After Finding Out About Her 5-Year Affair?

Family is meant to be a sanctuary of love and trust, but sometimes even those closest to us can shatter that bond. Imagine welcoming your pregnant sister into your home—out of love and support—only to discover she’s been involved in a five-year affair with a married man.

The shock of finding evidence of deceit, mixed with the chaos of a confrontation at your doorstep, left one sister questioning not only her trust but her very love for her sibling. In that moment, the sacred idea of unconditional family love was replaced with painful doubt and a need to re-establish boundaries.

Now, faced with undeniable proof of betrayal and conflicting narratives from a vindictive ex-wife and a desperate sister, the decision was made: love, at least for now, must be withheld. Rather than blindly accepting an untrustworthy version of her sister, the narrator chose to set clear limits—even going so far as to have her sign a tenant’s agreement. It’s a raw, heart-wrenching call for accountability when trust is so deeply broken.

‘AITA for Telling My Sister I Don’t Know if I Love Her After Finding Out About Her 5-Year Affair?’

Expert Opinion:

When trust is betrayed, it’s natural to feel conflicted about maintaining unconditional love. Renowned relationship researcher Dr. John Gottman has long emphasized that “trust is the cornerstone of any meaningful relationship, and once it’s broken, it must be rebuilt step by step.”

In this case, the narrator’s refusal to offer blanket forgiveness reflects a realistic understanding that love alone cannot override a consistent pattern of deception. Her decision to create boundaries is not just a knee-jerk reaction but an important step in safeguarding her emotional well‐being.

Breaking off unconditional affection doesn’t mean the bond is irreparable; rather, it signals the need for accountability and change. It’s important to recognize that while familial love is often considered unconditional, that does not equate to accepting harmful behavior. Dr. Gottman explains, “Healthy relationships require both emotional support and mutual respect.

When one party consistently undermines trust, it’s essential to re-evaluate the terms of the relationship.” This perspective is particularly pertinent here, as the narrator’s sister has repeatedly chosen betrayal over honesty, leaving little room for the simple act of love without boundaries.

Furthermore, relationship expert Dr. Elaine Rodriguez notes, “It’s perfectly acceptable—and sometimes necessary—to put one’s own emotional safety first. Boundaries serve as the foundation upon which trust may eventually be rebuilt, but they must be earned through accountability and change.”

In applying this principle, the narrator is not discarding love altogether; she is, instead, prioritizing the well-being of her family and herself over the toxic behavior that has come to define her sister’s actions. Establishing these limits sends a powerful message: while support remains available, trust and respect are non-negotiable.

The decision to have the sister sign a tenant’s agreement underscores a larger truth: when betrayal disrupts the very core of familial loyalty, redefining boundaries is both necessary and justified. As hard as it may be, such a stance can eventually pave the way for healing—should genuine remorse and accountability emerge.

Let’s dive into the reactions from Reddit:

In the aftermath of this revelation, many on Reddit expressed a mix of shock, sympathy, and even approval for the narrator’s tough stance. Some argued that maintaining unconditional love without accountability only enables harmful behavior, while others emphasized the importance of clear boundaries for the well-being of everyone involved. The consensus was clear: when trust is breached so profoundly, love must be re-evaluated.

This story is a stark reminder that even family bonds are not immune to the need for trust and accountability. When deception cuts so deeply, it’s understandable—and sometimes necessary—to take a step back and reassess the terms of your love.

While the narrator’s decision to withhold affection may seem harsh to some, it reflects a forward-thinking approach to protecting one’s emotional space and ensuring that trust is rebuilt only when it is truly earned. What would you do if faced with a similar betrayal in your family? Share your thoughts and join the conversation below.