Actor Liam Hemsworth and actress/singer Miley Cyrus arrive at the 2012 Vanity Fair Oscar Party at Sunset Tower on February 26, 2012 in West Hollywood, California. Credit: Jon Kopaloff/FilmMagic

Miley Cyrus has been called a lot of things, but there's one title she prefers: "I love being a 'fiancee,'" she announced via Twitter June 20.

Cyrus, 19, is engaged to her Last Song costar love of three years Liam Hemsworth, 22, who proposed in early June. The Hunger Games actor popped the question with a 3.5 carat diamond ring -- though he "did not ask her father, Billy Ray, for Miley's hand in a marriage," a source recently told Us Weekly.

Since accepting Hemsworth's proposal, Cyrus has been obsessed with her Neil Lane sparkler. "Will I ever quit staring at my finger?" she tweeted June 16.

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Though some worry Cyrus and Hemsworth are too young to handle the responsibilities of marriage, "They are both mature and ready for this," an insider countered. "Miley is 19 going on 40."

Furthermore, they have no immediate plans to tie the knot. "Right now they are enjoying being engaged," a Hemsworth pal told Us. "There is no rush."