Virtue and vice

[need help]

Hello!
Does anybody knows how to write a creative short story using the expression "virtue and vice"?

[Anglika]

Imagine sisters or brothers or friends, one of whom is good, and one of whom is not good. Now think up a situation in which you can show how each behaves and what happens.

Your story - you write it. We will comment on anything you write, if you care to post it in the forums.