Put on airs.
[Idiom] PUT ON AIRS. - Understand the Nuances of Pretentious Behavior
Act snobbishly.
The phrase "Put on airs" is used to describe someone who acts in a way that is artificially elegant, snobbish, or pretends to be more important or cultured than they really are. It's about adopting a manner intended to impress others.
Example Sentences
Don't put on airs, we're all friends here.
Don't act superior; we are equals here.
She's always putting on airs at parties.
She behaves arrogantly at social events.
Even though he won the award, he didn't put on airs and stayed humble.
Despite his achievement, he remained modest.