"She's convinced she'll spend the rest of her life with him. She's talking about a wedding as soon as she turns 18. She's even asked her mom if she can wear her wedding dress," the Sydney Morning Herald quoted a source as telling America's OK! Magazine.
Cyrus recently said: "He is awesome. We hang out almost every day. He's almost become like my best friend." She added: "He's a 6ft 4in Australian surfer, and I'm 5ft 4in, from Tennessee and I couldn't surf if someone gave me 10million dollars. So we couldn't be more opposite.
"But I went to Australia to visit him and his family, and I was like, Omigosh, this looks like Nashville. There were like cows everywhere. I am like, How are you from the opposite side of the planet and your world looks just like mine?"
The pair, who has been dating for 10 months, had met at the sets of their film The Last Song.