Hello Who, 'to pull a fast one on somebody" means to successfully trick or deceive someone. Examples: " Don't try to pull a fast one with me! I know what you're doing." " The con artist is trying to pull a fast one on the store." It means here he is trying to deceive and trick the store owner and sell him some forged or non original work of art for example. " We don't have to wait till April Fools' Day to pull a fast one on somebody."