Why pigs like satin always get the girl?

I'm a woman and that part of the movie bothered me. Here Sister had a man that loved and respected her, but she was blinded by the money and diamonds and look where it got her. The picture of a ring in the box was a very sweet gesture and it meant something. That she left it on the table was wrong! First thing to always remember is that if somebody tries to get you when they know that you're with somebody that shows a sign of disrespect. Second if they can cheat with you, they can cheat on you.