Conor McGregor is happy he has an ally in Justin Bieber , and is open to the Biebs walking him out into the octagon, Mayweather style.

We got Conor Saturday shopping for Rolex's on Rodeo Drive in Bev Hills ... and he had a lot to say -- about a re-match with Nate Diaz, whether he'll change his persona after his loss, and other stuff.