Wiktionary
have a bone to pick
vb. {{context|idiomatic|usually followed by (term with English)|lang=en}} To have a complaint or grievance (with somebody); to have a contentious issue to discuss.
Usage examples of "have a bone to pick".
We have a bone to pick with Baron Tellian, and I, for one, refuse to pretend we don't.
If they do, and humanity continues, let our grandfathers fight it out, if they have a bone to pick.