Why did Joe Jonas break up with Mandy Van Duyne?

Mandy Van Duyne lived next door to Joe Jonas when they were growing up. She inspired the song Mandy by the Jonas Brothers.

Joe thought they were better as friends rather than boyfriend/girlfriend. Also it wasn't Mandy Jiroux that he went out with it was a different Mandy who they grew up with, Mandy Jiroux is Miley Cyrus's best friend and not the same person.