AITA for refusing to attend my sister’s wedding because her fiancé stole my business idea?

A 28-year-old woman is torn about attending her younger sister’s upcoming wedding. Years ago, she shared a unique app idea with her sister — only to watch her sister’s fiancé launch an identical business, profit from it, and now use that money to fund much of their wedding.

She confronted them at the time, but they dismissed it as coincidence and refused to acknowledge any wrongdoing. Now the wedding is approaching, her parents are pressuring her to attend “for family,” and she’s been told (indirectly) that her sister expects her to photograph the event for free. Feeling betrayed and used, she’s considering skipping the day entirely. Is she the asshole for refusing to go?

‘AITA for refusing to attend my sister’s wedding because her fiancé stole my business idea?’

The betrayal happened years ago:

The confrontation was brushed off:

Now the wedding pressure is mounting:

Additional painful detail about expectations:

Stealing a business idea — especially one shared in confidence with family — is a profound betrayal of trust. Whether legally actionable or not, the emotional and financial harm is real. The fiancé profited from the OP’s intellectual labor, and the sister either knowingly or negligently facilitated it. Dismissing the accusation as “coincidence” without genuine discussion compounds the hurt.

The wedding creates a painful dilemma: attending could be interpreted as tacit forgiveness or endorsement, while skipping risks being labeled bitter or punishing the sister for her partner’s actions. Etiquette experts (including modern takes from Emily Post) agree that guests are not obligated to attend events that would cause significant emotional pain. Family pressure to “put it aside for family” often prioritizes appearances over justice.

The added assumption that the OP will photograph the wedding for free is another red flag — it shows continued entitlement and lack of respect. Relationship therapist Dr. John Gottman notes that unresolved betrayal erodes trust permanently unless met with accountability, apology, and repair. Here, none has occurred.

The OP is not the asshole for protecting her boundaries and refusing to celebrate a union partly funded by stolen work. Attending would likely deepen resentment rather than heal it. The sister’s wedding is her moment — but the OP’s dignity and self-respect come first.

Check out how the community responded:

The Reddit community overwhelmingly supported the OP — NTA — with most viewing the fiancé’s actions as theft and the sister as complicit.

Most called it unforgivable and backed skipping the wedding:

Many highlighted the added disrespect of expecting free photography:

Several questioned whether the idea was truly original but still sided with the OP’s right to boundaries:

Refusing to attend the wedding is not about punishing the sister — it’s about protecting personal integrity after a serious betrayal. The fiancé stole a business idea shared in trust, profited from it, and now uses that money to fund the very event the OP is expected to celebrate. The sister’s complicity (sharing the idea) and lack of accountability make forgiveness feel impossible.

Expecting the OP to photograph the wedding for free adds insult to injury — another sign of entitlement. Attending would likely deepen resentment rather than heal it. The OP is not obligated to smile through pain for family optics. Skipping is a valid boundary. Compassion for the sister does not require self-sacrifice. The right to say no exists — even on someone else’s big day.