It's been weekend of surprise cameos at the Coachella Valley Music and Arts Festival in Indio, Calif.
"Thanks coachella for showing so much love. Good times," he wrote.
"Right after his performance Bieber walked off stage and watched the rest of Chance's set with Selena Gomez," the source said. "They were there for around 15 minutes until Bieber touched Gomez on her mid back as if to say, 'Let's go,' and the two left together."
Bieber is one of the many musical stars making impromptu appearances at Coachella. Gwen Stefani stepped onstage with Pharrell, while Beyonce joined her sister, Solange Knowles, for a choreographed dance.