leave a bad taste in one's mouth - Phrases/Idioms
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Make a lingering bad impression on one, as in The argument left a bad taste in my mouth, so after that I avoided talking politics. This expression transfers the bad taste left by consuming bitter or otherwise unpleasant food to a distasteful experience. [Mid-1800s]