level with someone
Speak frankly and openly to someone, as in His companions advised him to level with the customs inspector. [Colloquial; early 1900s] Also see on the level.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.