For the past few days, Miley Cyrus and Justin Gaston have taken to their separate Twitter pages with messages of woe.

“Tears are words the heart can’t express,” Cyrus, 16, wrote Sunday night. Gaston, 21, tweeted the next morning, “How many tears are in there? They’ve gotta run out soon, right?”

The reason behind the tears was confirmed by a source. “They broke up on Sunday before she left for Savannah” to film Miley Cyrus’ new movie, The Last Song, the source told PEOPLE.

Miley Cyrus and Justin Gaston were last spotted at the Hannah Montana wrap party in Los Angeles last Friday. An insider said that “Miley introduced him to people” and didn’t say anything that they are having problems with their relationship.