"They've been friends forever and were there for each other when they were both getting separated, but they're just not in a romantic relationship anymore."
It comes just days after Carter "drooled" over braless photos of Cyrus at New York Fashion Week that were posted on Instagram.
Carter commented "dear god" along with a drooling emoji as Cyrus shared a flurry of sexy images from Tom Ford's show.
Cyrus and Carter first went public with their relationship in August, when pictures emerged online showing them kissing on a trip in Lake Como, Italy — one day after the Wrecking Ball singer announced her shock split with Hemsworth.
Cyrus and Hemsworth married in December 2018, after dating on-and-off for 10 years.
Cyrus and Carter were spotted on a number of occasions during their short time together, including a particularly amorous display in which they were "basically having sex" at celebrity hangout Soho House in West Hollywood.
Carter recently posted a photo of her and Cyrus together to celebrate Carter's 31st birthday.