The 26-year-old rapper found the Stan' hitmaker's music ''exciting'' and different when he was a youngster growing up in Detroit, and was thrilled to get the chance to collaborate with him on 'Detroit Vs. Everybody' years later.
He said: ''I bought his first CD at Costco with my mom when I was 11. He was a new breed of rap - he had fresh storytelling lyrics, full of drugs and murder. It was exciting. It was addictive. His music itself was like a drug. ''So you can just imagine what it's like to go from there to being in the studio with him, eating pizza and talking about which is better, 'South Park' or 'Family Guy'.''
Sean - who is dating Ariana Grande - has always been confident in his own abilities and was confident he'd be a successful rapper from the age of just 12.
He told Rolling Stone magazine: ''I've always been a dreamer. Since I was 10 years old, I was always rapping in front of the TV in the living room, visualising it all.
''[Did I think I'd make it?] I actually did. I never even questioned it. From 12 on, I used to always be like, 'And when I'm a rapper...' I was living in that world where I was already a rapper. People would make fun of me a little bit, but they would just be playing, though. They bought my CDs at school.''
He also slapped a jet-lagged Taylor Hawkins.
The acclaimed performer had just cancelled touring due to a battle with cancer.