Don't have a cow!
don't have a cow
slang Don't get upset. Don't have a cow—I'm sure we'll find a solution to this problem. I only borrowed one of your shirts, so don't have a cow!
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
Don't have a cow!
Calm down!; Don't get so excited! (Made famous in the television show, The Simpsons.) Chill out, man! Don't have a cow! Aw, don't have a cow, Dad!
See also: have
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.