"Flew in the face of" is an idiom that is often used to describe a situation where something goes against the norm, is contradictory or opposes what is generally expected. This phrase can be substituted and rephrased with other synonyms like defied convention, acted in defiance of, ran counter to or went against the grain. Each of these synonyms has a similar connotation of contradicting something that is usually taken as true or expected. They can be used in various situations when something goes against the norm or is considered to be unconventional, whether it be in social conduct, business practices or personal beliefs.