Justin Bieber and Selena Gomez are starting the new year single.

The on-again, off-again couple reportedly had a "nuclear argument" while in Mexico to celebrate New Year’s Eve and went their separate ways before ringing in 2013. A source tells the New York Daily News the two have yet to see each other since their fight. "They keep breaking up and getting back together," the insider says. "It's probably not correct to characterize this as a final breakup."

The two, who were photographed canoodling during a pre-Christmas trip to Salt Lake City, first called it quits on their two-year relationship in November.