Idioms and Phrases with put on an act
put on an act
Pretend, especially in order to deceive; also, show off. For example, We were afraid Charlie had hurt himself, but he was just putting on an act, or We know you're a good swimmer—stop putting on an act. [c. 1930]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.