That picture's so hot -- it's BLAZIN'!

Well isn't that just precious!

Usher and Justin Bieber cover Billboard's special edition May issue, looking like the true big-bro little-bro duo that they are!

The issue came out on Tuesday, to help promote Usher and the Biebs' upcoming performances on the Billboard Music Awards, which air May 20 on ABC!

Check out the mentor-protégé pic (above)!!!

The two super talented stars will both be releasing NEW highly-anticipated albums next month, with Usher's Looking 4 Myself out June 12 and Justin's Believe due out June 19!!

We can't wait to hear their collaborations on each other's albums!