"He has made me the happiest woman in the world!" Rose, 28, tweeted Thursday, linking to a picture of her engagement ring.
Rose, who collaborated with Khalifa, 24, on her debut single, "Fame," earlier this year, previously dated Kanye West. In an interview with Star magazine in January, Rose said she and West split in 2010 because of Kim Kardashian and called the reality star a "homewrecker."
