Sources close to the couple claimed the pair's busy schedules were the reason for the split.
"They are really good friends still and speak all the time, but their schedules just made it too difficult and it fell apart," an insider told Us Weekly. "[Chmerkovskiy] has a lot of respect for her, but it just wasn't working anymore."
Rumors that the model and the Dancing With The Stars alum were dating began in June as they were spotted on several dinner dates. The couple confirmed the relationship in September as they stepped out in New York City holding hands.
Later, Chmerkovskiy opened up about their relationship saying the 21-year-old model was "an amazing person."
"We have an incredible time together, and, you know, I definitely didn't see that coming and I think neither did she," he said. "We enjoy each other's company very much and like I said, she's a great girl that I never thought anything romantic like this could have happened."