The incident happened May 16 at the fast food restaurant on Bessemer City Road in Gastonia.
According to the Gaston Gazette, the suspect pulled up to the drive-through around 8 p.m. There was a woman in the vehicle with him.
The cashier says the man became angry when she told him the restaurant was out of chicken legs.
After going off, he allegedly pulled down his pants and boxer shorts, revealing his private parts before speeding off.
A manager was able to write down the suspect's license plate before calling police.
Police say they have identified the suspect, but are waiting on the cashier to press charges. If charged, the man will face a misdemeanor.