Egg on one’s face
This expression means to look foolish or embarrassed as a result of some gaffe or other, much as one would as a careless eater of eggs, with remnants of egg ending up on one’s face. Another explanation of its origin is from theatre audiences throwing eggs at bad actors. It has been established as American in origin, dating from the late 1930s. Post WWII, it soon found favour and usage on the other side of the Atlantic and across the English-speaking world.