upset the applecart
Meaning: If you upset the applecart, you do something that causes trouble or upsets someone's plans.
- The Stones upset the applecart by pulling out of the music festival. They were going to be the main act.
- Kelly's sister really upset the applecart when she told Kelly that she'd seen her husband waiting for someone in a hotel lobby when he was supposed to be in New York.
We'd planned to have our wedding in the local park, but the head of the council upset the applecart when he