the fur will fly

the fur flies

There is an argument. When the fur flies, I'm making myself scarce—there's no way I'm getting roped into a fight between those two. You can be sure that the fur will fly if the president vetoes the bill that both sides of congress worked so hard to pass.
See also: flies, fur
Farlex Dictionary of Idioms.

the fur will fly

there will be serious, perhaps violent, trouble. informal
This phrase originated in the early 19th century, in the US. The image is of a furious fight between dogs or cats.
See also: fly, fur, will
Farlex Partner Idioms Dictionary

the ˌfeathers/ˌfur/ˌsparks will ˈfly

(informal) there will be anger, annoyance, etc: The fur will really fly when she tells him he can’t go out tonight.
See also: feather, fly, fur, Sparks, will
Farlex Partner Idioms Dictionary
See also:
  • be at a disadvantage
  • address (one's) comments to (someone or something)
  • address comments or remarks to
  • at a disadvantage
  • address (one's) remarks to (someone or something)
  • be in it for
  • be more than (something)
  • be more than glad, ready, etc.
  • away from it all
  • be out of (one's) head