part over (something)
To separate from or discontinue one's association with someone due to some problem or disagreement. You two have been together for such a long time—it would be a shame to part over such a silly argument! The business partners decided to part over differing opinions as to how the company should be run.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
part over something
[for people] to separate because of something. We had to part over our disagreement. They parted over a very small matter.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.