AARON RODGERS reportedly made a bet with the guys in BOYZ II MEN that if his Packers lost to the San Franciso 49ers this past weekend, he'd wear the jersey of Niners QB ALEX SMITH.  Well, the Niners DID beat the Packers . . . and Rodgers is reneging.

He blames the media for making it more than it was . . . quote, "There's nothing to that.  That got blown way out of proportion.  It was at best a joke between friends, and, unfortunately, the great reporting of TMZ blew another one."

But Boyz II Men singer NATHAN MORRIS thinks Aaron will come through . . . quote, "Aaron might be one of the classiest guys we know."