it's not kosher

it's not kosher

It isn't fair, sportsmanlike, or legitimate. I know you want to avoid confrontation, but it's not kosher to break up with someone by text message. I don't see why you think it's not kosher. People do it all the time!
See also: kosher, not
Farlex Dictionary of Idioms.
See also:
  • it's just not cricket
  • it's not cricket
  • kosher
  • not cricket
  • not cricket, it's/that's
  • koshe
  • keep kosher
  • May the best man/woman win.
  • break a lance
  • lance
References in periodicals archive
Aside from the fact that it's not kosher, we could find little reason to fault this bread.
Barry's best bread for the Challah-days
The following is a sampling of those expressions: "I'm not happy with the principle, it's unethical." "If the pay was better it might be more palatable." "There's no choice if you want to work for them." "I signed with a bad taste in my mouth." "If I take a stand against them a hundred other writers will be there to take my place." "It's a hold-up, it's not kosher."
Electronic wrongs