Along with a cover of industry pal Taylor Swift's "I Knew You Were Trouble," she also performed a rousing rendition of Justin Timberlake's ultimate breakup anthem: "Cry Me a River."
"I’ve kind of been through a lot these past couple of months, and it’s been really interesting and fun at the same time – and weird and sad, but cool," Gomez, 20, told the audience gathered Saturday night before launching into the 2002 pop single. "This song has helped me through a lot, and if anybody knows 'N Sync or, you know, some J.T., you’re gonna know what I’m talking about. But this song definitely speaks to me."
Of course, true Be-liebers know who made the first move: At his November concert in Boston, Bieber, 18, grabbed his acoustic guitar for a stripped-down version of Timberlake's hit, which takes on the feeling of finding out a partner has been cheating. (According to Vulture, he also covered the song in 2008.)
Watch the former couple try their hands at Timberlake's tune, and tell us in the comments below: Who deserves a standing ovation?
Reporting by GABRIELLE OLYA