Liam Hemsworth and Miley Cyrus are calling it quits—for real this time. The famous fiancés had been on again, off again for a while, but their official breakup comes weeks after an intervention from Hemsworth's brothers. Chris and Luke Hemsworth were concerned about their 23-year-old brother's engagement to the 20-year-old pop star, who's inconsistently worn the 3.5-carat diamond ring he gave her when he proposed last June. Tabloids floated the rumor that Liam Hemsworth had some sort of dalliance with Mad Men star January Jones.