I was just talking about this with a friend. Some parents have insane expectations for their children. Second, they are not so quick to forgive the faults of whoever is with their children. This is why it's best to not involve parents in disagreements because even though the couple will move on, the parent will hold the grudge forever. Hopefully the parent will come to terms with the boyfriend / fiancee after their marriage.
ThanksVey true @sarahtops9000