James Harden: No Khloe Blues ... All About The Future

So your girlfriend just broke up with you in front of the WHOLE WORLD to get back with her estranged husband ... what do you do?

If you're James Harden ... TURN UP!!!

The Rockets star ... who you'd think would be bummed out that Khloe Kardashian put the brakes on their relationship and called off her divorce to Lamar Odom ... must want us all to know that he's A-OK.

JH posted a video to his Instagram jamming out to Drake & Future's song, "Jersey," and we gotta admit ... he looks happy as a clam.