This is getting out of hand ...

Usher is showing off his rock hard abs and some serious manscaping -- just a few weeks after The Game's huge pic blew up the Internet.

We're guessing it's not a direct response, since Usher opted for less showy black briefs. His real reason for sharing was purely inspirational -- "Workin' hard so I can eat this turkey."

As Ush put it ... U don't have to call. But you probably will after seeing this.