shitting in someone's Cheerios
Spoiling someone's morning
To shit in someone's Cheerios is to ruin their mood or spoil something for them, especially early in the day or before they've had a chance to enjoy it.
The image is of contaminating someone's breakfast—their fresh start: Who shit in your Cheerios? suggests someone is inexplicably grumpy or hostile.
Sorry to shit in your Cheerios, but the meeting's been moved to Monday.
- disappointmentSadness from unmet expectations
- antagonismActive opposition or hostility
- obstructionSomething blocking the way
- meddlingIntrusive interference in others' concerns
- discouragementLoss of confidence
frustration · party pooper · mood killer · hostility · sabotage · bad faith · rudeness · undermining · rubbing salt in the wound · irritation · hindrance · buzzkill · disrespect · throwing a wrench in the works · resentment · sour grapes · offense · disruption