Riff Raff just learned Southern hospitality only goes so far ... he was arrested early Sunday morning in North Carolina after cops found drugs in his car.
The rapper was tooling around Greensboro at around 2:30 AM and bizarrely stopped in the middle of traffic to talk to a bunch of pedestrians ... and if we know our Riff Raff, we're guessing he was pimpin' it.
Cops approached the vehicle and say they saw an open container of alcohol, which then triggered a full-blown search of the vehicle. That's when police say they found weed and some sort of powerful narcotic, along with drug paraphernalia.
The former MTV reality star (who may or may not have been the inspiration for James Franco's character in "Spring Breakers") was arrested along with his 2 passengers and taken to jail, where they were booked and released without bail.
Cops say Riff turned on the Southern charm, because he was "not aggressive and polite."