"She broke it off with him," a close source told E! News.
A second insider added that there's no "bad blood" between the pair, they've just decided that they're "not meant to be a couple."
"Demi loves being in a relationship, but she is ready to be single for a little while," they added.
The 24-year-old was first linked with the 31-year-old MMA fighter last July when the pair enjoyed a “quick fling", PEOPLE reports.
After ringing in the new year together, they made their relationship social media offish and have been spotted together on many occasions over the past few months.
Dems even gushed about her bae on The Ellen DeGeneres Show recently, telling the host “Isn’t he cute? He’s so cute! I’m very happy. Life is really good.”
The "Cool For The Summer" singer has since deleted their couple pics from her Insta to start fresh as a single gal.