piss in someone's cereal
Proposed by a contributor, not yet supported by evidence.
Meaning · English
to spoil or ruin someone's plans or event
Literally: urinate in someone's breakfast cereal
Where it’s used:
Used
Widespread English
Examples
His negative attitude really pissed in our cereal on the day of the party
AI-drafted example auto-approved by rule (illustrative, not a corpus attestation)
Sources & notes
Listed in Wiktionary’s “English idioms” category (retrieved 2026-07-29); definition pending editorial review. Definition drafted by AI (@cf/meta/llama-3.3-70b-instruct-fp8-fast) and auto-approved by rule on 2026-07-31; pending editor spot-check.
Common questions
What does “piss in someone's cereal” mean?
to spoil or ruin someone's plans or event Literally: urinate in someone's breakfast cereal
Is “piss in someone's cereal” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.