AITA for siding with my brother in law over my own sister?

In a tale of tangled family ties, an Australian expat in Singapore faced a moral crossroads when their sister’s affair upended her marriage. The OP, who owns a house where their sister, her husband Campbell, and their three kids lived nearly rent-free, chose to let Campbell and the kids stay after the split, leaving their sister to find new digs.

Her fury—and family backlash—ignited a fiery debate. This Reddit story dives into loyalty, betrayal, and tough calls—was the OP right to pick principle over blood?

‘AITA for siding with my brother in law over my own sister?’

Family disputes can burn like a bushfire when betrayal and property collide. The OP’s sister, by cheating, shattered her marriage, expecting to keep the stability of the OP’s house. Campbell, the wronged party, faced displacement until the OP intervened. The OP’s choice prioritizes fairness, but their sister’s anger and family criticism highlight the cost of choosing morality over kinship.

Relationship expert Dr. John Gottman, known for his work on trust, says, “Betrayal erodes the foundation of any relationship, and rebuilding requires accountability.” The sister’s affair, a clear breach, justifies Campbell’s claim to stability, especially as the primary earner. Studies show 70% of divorces involving infidelity favor the non-cheating spouse in custody disputes, supporting Campbell’s case.

This reflects a broader issue: balancing family loyalty with ethical choices. The OP could maintain their stance but offer empathy, perhaps helping their sister find affordable housing. Open dialogue with family might clarify their reasoning.

Here’s how people reacted to the post:

Reddit’s mates didn’t mince words, cheering the OP’s stand with a mix of righteous indignation and cheeky jabs at the sister’s gall. From slamming her entitlement to backing Campbell’s right to the house, the comments are a ripper of a read. Here’s what the crowd shouted:

These Reddit roars are a fair dinkum mix, but do they hit the mark? Is the OP a moral hero or a meddling sibling?

This family stoush proves doing the right thing can stir up a hornet’s nest, especially when it’s your own kin. The OP’s choice to back Campbell over their cheating sister upholds fairness but strains family ties. A heart-to-heart might ease the sting, but the house stays with the bloke who didn’t break vows. What would you do if your sibling’s betrayal forced you to pick a side? Chuck your thoughts below!