A Northern Territory man may be flown to Adelaide after a party trick involving setting off fire crackers between his buttocks went badly wrong.

The 23-year-old man was at a party in the Darwin suburb of Rapid Creek on Saturday night when he decided to let the cracker off, NT Police said.

"It appears a party was in full progress when a young male decided to place a firework between the cheeks of his bottom and light it," said Senior Sergeant Garry Smith.

"What must of seemed to be a great idea at the time has backfired, resulting in the male receiving quite severe and very painful burns to his cheeks, back and private bits," Snr Sgt Smith said.

Alcohol was a possible factor involved in the stunt, police said.