pee in (someone's) Corn Flakes

rude slang To really upset, irritate, or disappoint someone. Sorry to pee in your Corn Flakes, but you won't get any credits for the class unless you attend every single lecture. A: "Watch out, the boss is in a foul mood today." B: "Wow, I wonder who peed in his Corn Flakes?"

Common Names:

Name	Pronounced	Usage
Rolando	ro-LAHN-do (Spanish)	Spanish, Italian, Portuguese
Bronislava	brah-nee-SLAH-vah (Russian)	Czech, Slovak, Russian
Xochiquetzal	-	Aztec and Toltec Mythology
Iona (1)	ie-ON-ə (English)	English, Scottish
Glorinda	glo-REEN-dah	Esperanto
Noortje	NO:R-tyə (Dutch)	Dutch, Limburgish