Looks like she's single for real now...

Singer Ariana Grande has split again with boyfriend Jai Brooks, a source tells E! News.

The couple broke up last month, says the source, who adds, "When her grandfather was dying, everyone was there for her. People flew to Florida to be with her, but Jai didn't. Ariana just felt he wasn't there like he should have been."

The singer posted a message on Twitter Sunday that some speculate was inspired by Brooks. "July was painful for many reasons but of all the personal loss I suffered last month, the loss of my grandfather, a true gentleman, was the only one that truly mattered," she wrote, in part. "I thank my loves for being so in tune to what is good and right for me and my heart."

"I hope you will surround yourselves with people who will be there for you thru the bad times, not just the good," she added. "I thank everybody who was here for me when I needed them as the ones who weren't really broke my heart."

The two dated from August 2012 to July 2013 but reconciled earlier this year, and still remain friends, according to a source.