on the outs

No longer on friendly terms, as in They've been on the outs with their in-laws for years. This idiom appeared in the early 1900s and derives from the synonymous at outs, first recorded in 1824.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.