The "Senorita" star has teamed up with Bieber for his latest release, which drops on Friday (November 20), and, speaking to Zane Lowe on Apple Music, Shawn admits he's always been a massive fan of his newfound pal.
Of the single, he says, "I think I was coming off the back of a couple of big songs and definitely just so driven by my ego and just feeling like something in this feels not right."
"This song has always resonated with me and it just never found its way out," he explains. "And now all of a sudden I was listening to it one day, and I just started my relationship with Justin."
Shawn says his relationship with Justin only began in the past three months, with the singer sharing, "I called him and I was like, 'Look, I have this song. It's kind of going there.' We go there. It's about how society can put celebrities up on a pedestal and watch them fall and it seems to be this entertainment thing. And it's hard. And his heart fell deep into it."
"Him and I, even yesterday, were on the phone for an hour and had the deepest conversation, I think, about so much," he recalls. "And it just felt really nice because it was a full circle moment for me, this guy who was the reason I started singing."
Shawn, who is also a Canadian like Justin, continues gushing about his collaborator, "I was nine when 'One Time' came out, and I completely was all in. He was Elvis to me. And to come back around and to have this very human to human conversation with him and his truth to come into that song and my truth to be there, it feels like one of the most special songs I've ever wrote (sic)."