AITA for not helping my brother and my ex with the kid they had together and telling my parents to step up if help is deserved?

Discovering infidelity is painful enough, but finding out your partner cheated with your own sibling takes betrayal to another level. For one man, that shock didn’t end with the breakup. It followed him into months of emotional pressure, family arguments, and a baby he was expected to care about despite everything that had happened.

What makes this situation especially tense is the role his parents now play. While they insist the baby’s wellbeing should outweigh past betrayals, he believes stepping back is the only way to protect his peace. As the story spread across social media, readers weighed in heavily, debating loyalty, responsibility, and whether “family” should always come first.

Everything unraveled after years of what the poster believed was a stable relationship

After the breakup, the situation took an even darker turn once pregnancy entered the picture

When the results came back, the truth was undeniable

Months later, his parents pushed him again, this time framing it as a moral obligation

His response was blunt and final

This conflict highlights a painful clash between emotional trauma and family expectations. From the poster’s perspective, cutting contact is an act of self-preservation after deep betrayal. Trust was broken by both his partner and his brother, followed by attempts at deception involving legal documents and parenthood. For many people, that crosses a line that cannot simply be repaired by time.

From the parents’ point of view, the focus has shifted entirely to the baby. While understandable on a human level, this mindset can unintentionally minimize the emotional harm done to their other child. Family systems often default to damage control rather than accountability, especially when an innocent child is involved.

Relationship researcher Dr. John Gottman has explained that betrayal fundamentally changes how people feel safe in relationships. As he notes, “Trust is built in very small moments, and it’s broken the same way.” In this case, the repeated lies and pressure eroded any remaining sense of safety the poster had with his family.

Practically speaking, experts often advise separating compassion from obligation. Acknowledging that a child is innocent does not automatically create responsibility for someone who was wronged. Healthy boundaries allow individuals to heal without being forced into roles that reopen emotional wounds. Long-term, respecting those boundaries may be the only way to preserve any chance of future reconciliation.

Here’s the feedback from the Reddit community:

Many users rallied behind the poster, urging him to protect his peace after such a deep betrayal

Others focused on the parents’ role and the pressure they were applying

Some responses were blunt, emotional, and brutally honest

This story lays bare how betrayal can fracture families far beyond the original act. While the baby is innocent, forcing responsibility onto someone who was deeply wronged may only create more damage. Compassion does not have to mean sacrifice without consent. In a situation like this, where would you draw the line between family duty and protecting your own mental health?