Bageshwar Dham Sarkar
What is the duty of a true friend, and what kind of friends should I avoid?
A friend's duty: treat his sorrow as greater than yours
A true friend treats his own mountain-like sorrow as small and his friend's small sorrow as very big, and helps. Bhagwan Ram showed this in his friendship with Sugriv and Vibhishan.
One who considers his own mountain-like sorrow small, and his friend's small sorrow very big, and helps and supports his friend, is a true friend.