A US girl's snarky Facebook post has cost her father USD 80,000 he had won in a legal settlement.

Patrick Snay, 69, a former headmaster of Gulliver Preparatory School in Florida was set to receive the amount after settling a 2011 age discrimination suit with the school he once headed.

However, his daughter, Dana ruined the USD 80,000 deal by blabbing about it on Facebook, the 'Miami Herald' reported. "Mama and Papa Snay won the case against Gulliver. Gulliver is now officially paying for my vacation to Europe this summer. SUCK IT," she wrote.

The message circulated among the former Gulliver student's 1,200 Facebook friends and eventually made its way back to the school. The school claimed the post violated the settlement's confidentiality agreement.

A judge last week tossed out the settlement, ruling the ex-employee and his daughter breached the terms of a confidential agreement when she took to social media to brag about it, the report said.