To have egg on your face

To look foolish or be embarrassed because of something you have done

e.g. a new work colleague had egg on his face; his job application form stated he had several IT/computing qualifications but on his first day on the job it became apparent that he couldn’t even use a spreadsheet.

To have egg on your face usually has a negative connotation even though it’s been a cosmetic remedy for facial blemishes for at least 300 years.
In a newspaper article from April 1974 titled, “Keep Those Tapes Rolling” Jerry Buck interviewed American television host and media mogul Merv Griffin. Discussing how his television shows ran, Merv Griffin had this to say about the process:
We never stop the taping. I don’t care if the walls fall down. My orders are to keep the cameras going, even if I’ve got egg on my face.
In 1936, there was a news story titled, “Show Hostess You Enjoy Her Hospitality” written by Emily Kimbrough. The idiom egg on my face was used within the context we use today.
The American Management Association included this idiom in an article in their journal in 1934, warning those in managerial positions not to ignore or overlook problems as they came up.
If you try to sweep it under the rug, everyone ends up with egg on their faces.