Wild pack animals will eat from a carcass only after the alpha male has finished.
Having a bone to pick establishes superiority and comes from an ancient Sicilian wedding ritual.
At dinner’s end, the bride’s father would give the groom a bone and instruct him to pick it clean.
This ritual signaled the groom’s authority over his new wife, establishing that in all future decisions, he would have the final word.
When looking for a showdown or fight, we often say, “I’ve got a bone to pick”.