Miley Cyrus Reveals the Moment She Knew Her Engagement Was Over

(Photo Credit: Jon Kopaloff/FilmMagic/Getty Images)

Valentine's Day is usually a day for celebrating love with a significant other - but not for Miley Cyrus, who said that was the day she knew she and former fiance Liam Hemsworth were done.

Cyrus spoke with Fashion Magazine for its November issue, which hits newsstands Oct. 7, and said her new song "Drive" was written about Hemsworth in February, months before their split in September.

Read: Miley Cyrus Breaks Down During 'Wrecking Ball'

"I wrote ["Drive"] while I was working on Valentine's Day-emotionally it was such a hard time," she told the magazine. "It is about needing to leave someone but not really wanting to completely cut yourself off from the relationship," she added. "It's a time when you want to leave but you can't. It's also about moving on."

And move on she eventually did.

After a shocking VMAs performance by Cyrus - the twerk heard 'round the world - and months of speculation that the couple were indeed over, the couple announced Sept. 16 that they had split.

Related: Miley Cyrus and Liam Hemsworth Call Off Engagement

The couple met in 2009 on the set of the film "The Last Song," and got engaged in the summer of 2012.

Cyrus also brought the claws out a bit and told the magazine that other pop music princesses better watch their back because she's the queen.

"What I wear adds a factor that other girls can't compete with," she added.