Shit in my salad
To ruin somebody's day, job, idea or creation. To ruin something.
Example #1 - Jerry just took a big shit in my salad when he told the boss that it was my idea to only hire undocumented laborers.
Example #2 - That waiter shit in my salad when he shit in my salad.
Example #2 - That waiter shit in my salad when he shit in my salad.