explain wickhams comment on darcy

Wickham commens on Darcy because when the three accidentally cross paths, there is a definite coldness and ill at ease. Wickham then tells Elizabeth that the reason for the mutual embarrassment when he and Darcy met is that Darcy's father had promised that Wickham, his godson, should be given a good living after his death, but that Darcy had failed to fulfill his father's dying wishes and had left Wickham to support himself.