AITA for not supporting my brother’s relationship with my cheating ex and not attending their wedding?

A family feud erupted when a man discovered his brother was dating his cheating ex. After a painful breakup three years ago, the 25-year-old was shocked to learn his 26-year-old brother was now engaged to the woman who betrayed him repeatedly during their five-year relationship. His refusal to support their wedding has split the family, with his sisters backing him and others pleading for peace.

The decision to boycott the backyard wedding has ignited heated arguments, with the brother dismissing the man’s pain as immaturity. Torn between loyalty to himself and family pressure, he’s standing his ground, but the emotional toll is heavy. This raw story of betrayal, sibling rivalry, and moral conviction pulls readers into a messy debate about forgiveness and boundaries. Was he right to take a stand, or should he let it go?

The heartbreak began three years ago when the man caught his ex cheating repeatedly.

His brother’s new relationship with the ex blindsided him, sparking feelings of betrayal.

Family opinions split, with some supporting the man while others urged reconciliation.

The wedding announcement pushed the man to take a firm stand against attending.

Family pressure intensified, but the man held firm, questioning his brother’s loyalty.

The man’s refusal to support his brother’s wedding stems from deep hurt and a sense of betrayal. His ex’s repeated infidelity shattered his trust, and his brother’s choice to marry her feels like a second blow, especially given their close sibling bond. The man’s decision to boycott, supported by his sisters, reflects a need to protect his emotional well-being, while the family’s push for unity highlights differing views on loyalty and forgiveness.

Psychologist Dr. Harriet Lerner notes, “Betrayal by a sibling can feel as profound as romantic betrayal, as it violates family trust” (The Dance of Connection, 2001). The brother’s dismissal of the man’s pain as immaturity suggests a lack of empathy, which fuels the conflict. Socially, many view dating a sibling’s ex—especially one with a history of cheating—as a breach of loyalty, as reflected in supportive online comments.

The family’s pressure to “let it go” may stem from a desire to avoid conflict, but it risks invalidating the man’s feelings. His brothers’ suggestion to let the marriage fail naturally ignores the emotional toll of attending a wedding tied to his trauma. A healthier approach would have been for the brother to acknowledge the man’s pain before pursuing the relationship, fostering open dialogue.

The man’s stance is justified, but a conversation with his brother—calmly explaining his hurt and setting boundaries—could clarify intentions. If the brother remains dismissive, the man is wise to prioritize his peace. Moving forward, he should lean on supportive family members, like his sisters, and consider therapy to process lingering pain from the breakup and this new betrayal. The family must respect his boundaries to heal the rift.

Check out how the community responded:

Many users backed the man, condemning his brother’s lack of loyalty.

Some users dug deeper, questioning the brother’s motives or the story’s context.

A few brought humor to lighten the heavy mood.

The man’s refusal to attend his brother’s wedding to his cheating ex has torn his family apart, highlighting raw wounds and clashing loyalties. His stance, backed by his sisters, prioritizes his emotional health, while his brother and other family members dismiss his pain, urging forgiveness. Social media users largely support him, though some suspect hidden layers to the betrayal.

The situation raises questions about family loyalty and healing from past hurts. Should he hold his ground, or try to mend the rift? How would you navigate this family drama?