Shawn Mendes joined forces with rapper A$AP Rocky for an impromptu duet about nice clothes while backstage on Oct. 6.

The 17-year-old star and the Harlem-born rapper were both headliners at the Forbes Under 30 Musical Festival in Philadelphia, and they seemed to enjoy spending time together backstage, reported MTV.

The singer shared a video on his Instagram account of himself playing acoustic guitar while the 27-year-old hip-hop star rapped about expensive designer clothing.

"Look at what I bought / Dior is the coat / you know what it cost," Rocky can be heard rapping, while Mendes strums a beat and eventually joins in with a hook.

A video posted by Shawn Mendes (@shawnmendes) on Oct 6, 2015 at 11:48am PDT

In other news, Mendes recently scored his first Top 10 spot on the Hot 100 Billboard charts with his popular hit "Stitches."

The song currently sits at No. 9 on the charts, making Mendes one of four Canadian stars to currently hold a top 10 spot. The Weeknd holds the No. 1 spot with his song "The Hills," followed by Justin Bieber with his single "What Do You Mean?" and rapper Drake, whose song "Hotline Bling" holds the third spot.

In August, Mendes discussed his song breaking into the Top 40 and the effect it has had on his fans, reported Billboard.

"It's not easy to have a radio hit," Mendes said. "You can feel the difference between 'Stitches' and my other songs -- when I'm opening for Taylor Swift shows, they'll know the song when I play it. 'Stitches' is very me, and it has connected with my fans in the way I wanted it to. It's a great feeling."

On July 28, the singer released an acoustic version of the popular song with actress and singer Hailee Steinfeld, which was met with a lot of praise from fans.