Jealousy

Jeal·ous·y   [jel-uh-see] noun, plural -ous·ies for 4. 1. jealous  resentment against a rival, a person enjoying success or advantage, etc., or against another's success or advantage itself.

I just learned of a sibling's jealousy ... a brother questioned something he learned about one of my grandchildren ... it was an ugly accounting but the bottom line is ... he's jealous. Therefore, I will look the other way. There is no way I can make this better ... I just consider the source and move on. Like us all, he's on a journey and perhaps, one day, our journeys will mesh and I can share the joy of grandchildren when it isn't such a source of pain for him.

It seems like the simplest way.