The 'No Tears Left to Cry' singer and the 26-year-old rapper - who went public with their romance in August 2016 - have decided to go their separate ways but will remain ''the closest of friends'', sources told TMZ.
Insiders explained the pair decided to split after their work schedules became too busy but they still ''love each other dearly'' and are determined to stay best friends.
News of the split comes just a few weeks after Mac praised Ariana on Twitter when she made her musical return with new single 'No Tears Left to Cry'.
Along with a heart emoji, he posted: ''very proud of this girl right here.
''Welcome back. We missed you.
''One of a kind.(sic)''
The two were last photographed together holding hands at Madonna's Oscars afterparty in March.
Ariana first met Mac when they recorded 'The Way' together in 2013, and the 24-year-old pop star admitted last year she had had feelings for him for a long time before they got together romantically.
She said: ''We have loved and adored and respected each other since the beginning, since before we even met, just because we were fans of each other's talent.''
And the two stars have worked together since then, including on Mac's track 'My Favorite Part', while they shared the stage together to perform 'The Way' and 'Dang!' at the One Love Manchester concert, which Ariana staged last July in the wake of the terrorist attack at her concert in the English city last May.
And Mac previously spoke of how much he enjoyed working with Ariana.
He said: ''Just because we are two people who are in love and have a great relationship doesn't mean I am going to get weird about this incredible music we make.
''I'm here to talk about music and I happen to be in a fantastic relationship with someone I also enjoy making music with so those lines can get blurred very easily on what I am here trying to do.''
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