Mac Miller sadly died on 7 September, aged 26.
The pair dated for nearly two years and recorded multiple songs together, including "My Favorite Part and "The Way".
While Ariana hasn't said a lot about Mac's death, some people online laid the blame on her, due to their breakup earlier in the year, which some fans claim was the reason for his continued drug use.
The No Tears Left To Cry singer, 25, posted a captionless black and white photograph of Miller looking up at the camera on her Instagram account, which has also had the comments disabled. Both players took to Twitter to express their personal sense of loss over Miller's untimely passing.
Miller, 26, died of an apparent overdose at his California home Friday afternoon. "I respect and adore him endlessly and am grateful to have him in my life in any form, at all times regardless of how our relationship changes or what the universe holds for each of us!"
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Less than a week after the split, Miller - who had long battled substance abuse and addiction - was arrested for driving while drunk after he crashed his SUV and fled the scene.
"I have cared for him and tried to support his sobriety and prayed for his balance for years (and always will of course) but shaming/ blaming a woman for a man's inability to keep his s*** together is a very major problem".
An autopsy and toxicology report is being performed to determine Miller's exact cause of death.
As it was previously reported, Miller and his ex-girlfriend, Ariana Grande, broke up in May after dating for two years.