Offset made a jewelry run in NYC, with his gf Cardi B apparently in tow, but made it clear he wasn't icing her up ... 'cause he doesn't need to anymore.

The Migos rapper came out of the jeweler Wednesday afternoon loaded down with a new pendant and 3 flashy watches worth at least one exotic sports car. When we asked if any of the new gear was for Cardi ... Offset had the perfect response -- especially because we're pretty sure she was in earshot, waiting in their ride.

Well, we know he's bought her bling before ... but that was B.B.Y. -- before "Bodak Yellow" blew up.