You shouldn't associate with someone that lies.
Tim has a classmate that regularly lies and steals from other classmates.
Tim wants to confront the classmate about her lying habit.
Tim tells the classmate to stop lying and ceases contact with them.
Tim tells the lying classmate that he wants to be friends with them, and he forgives them.
Tim is glad the situation is handled and the classmate feels sad.
Tim enters an abusive relationship with the classmate, and regrets doing so.