kiss and make up
Settle one's differences, reconcile, as in The two friends decided to kiss and make up. This colloquial expression has largely replaced kiss and be friends, dating from the 1400s. [Mid-1900s]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.