Jason Derulo & Kelly Rowland - Billboard Music Awards 2013!

Jason Derulo shows off his buff arms while walking the blue carpet in a tank top at the 2013 Billboard Music Awards held at the MGM Grand Garden Arena on Sunday (May 19) in Las Vegas.

The 23-year-old “Other Side” singer hit the stage during the night to present the award for Top Billboard 200 Album of the Year alongside Emmy Rossum.

Kelly Rowland showed off some leg while walking the carpet that night. She presented the award for Dance Artist of the Year alongside Austin Mahone.

FYI: Kelly is wearing a Rami Al Ali dress.

15+ pictures inside of Jason Derulo and Kelly Rowland at the show…