Nature is fair for everybody. Every girl has her chance to be a wife, and also has her chance to be mistress.

No need to argue about it. Only when you have been both sides you would realize how stupid to even talk about it.

Every married person (man and woman) should have his/her moral obligation for their family. Some people may not, it is not the mistress's fault. It is the betrayed person who needs to be punished!