@Chizan
Again the problem isn't that he didn't want to marry her the problem is how he did it. Saying i don't love you and I want someone else =/= Spreading malicious lies about her trying to have someone assassinated and bullying someone.
@Chizan
Yes it is a bad thing too insult one of your biggest supporters and nobles daughter in public spreading false rumors that will Damage not only her image but also her family. Now rivals families and factions can use it to lessen legitimacy. Wars have been fought over for less.