piss in (someone's) Cheerios

rude slang To really upset, irritate, or disappoint someone. Sorry to piss in your Cheerios, 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 pissed in his Cheerios?"

Common Names:

Name	Pronounced	Usage
Kajsa	KIE-sah	Swedish
Chisomo	chee-SO-mo	Southern African, Chewa
Elisabeth	e-LEE-zah-bet (German), e-LEE-sah-bet (Danish), i-LIZ-ə-bəth (English)	German, Dutch, Swedish, Norwegian, Danish, English, Biblical, Biblical Latin
Johanna	yo-HAH-nah (German), yo-HAHN-nah (Danish, Dutch), YO-hahn-nah (Finnish)	German, Swedish, Norwegian, Danish, Dutch, Hungarian, Finnish, Estonian, English, Late Roman
Quintus	KWIN-tuws (Ancient Roman), KWIN-təs (English)	Ancient Roman
Ladislava	-	Czech, Slovak