It's always good to repay others what you owe them.
Zach is low on money and still owes his friend Tim $100 but his rent is due in a few days.
Zach wants to pay his rent on time.
Zach paints his parents' fence in order to earn some extra cash and is able to pay his rent and repay Tim.
Zach fails to pay Tim back the money he owes in order to afford his monthly rent.
Tim is happy that Zach followed through with his commitment to repay him, and they remain good friends.
Tim gets upset that Zach won't pay him back and stops hanging out with him.