Miley Cyrus posts racy cleavage-baring corset Twitpic

Over the weekend, Miley Cyrus posted a picture of herself wearing a tight corset with her breasts practically spilling out the top to Twitter. Despite a mostly positive response from fans who gushed about her tiny waist, the photo has since been removed.

Cyrus has been busy pushing a new, sexier profile for the past year or so and recently has been tweeting lots of messages about the bondage erotica bestseller "50 Shades of Grey," which is currently in development as a major motion picture and in need of a young star to take on the main role.

What do you think? Is Miley -- who recently announced her engagement to boyfriend Liam Hemsworth -- growing up too fast? Or is she just mature, as one close friend tells Us magazine, for her age?

"She's very mature! She's 19 going on 40, so she is ready for [marriage]," a source tells the magazine.