Ariana's known to constantly refer to Mac as an "Angel" and referenced the "demons" he fought in his life:

"My imagination's too creative / They see demon, I see angel, angel, angel / Without a halo, wingless angel"

She also references the fact that she couldn't imagine losing him at such a young age, and also the self-care she needed to consider when she exited the relationship after Mac couldn't stay sober:

"Falling, falling, but I never thought you'd leave me / Falling, falling, needed something to believe in, oh

 Your Gucci tennis shoes runnin' from your issues / Cardio good for the heart (For the heart, for the heart) / I figure we can work it out, hmm."

What really seals the deal is this line about wanting to see Mac break out of his bad habits:

"Wanted you to grow, but, boy, you wasn’t budding / Everything you are made you everything you aren't"

So, so rough.