A 26-year-old man has been jailed for five years for stabbing in the head another man who bared his backside as a taunt.
Jay Jay Hind dropped his trousers during a confrontation in Russell Rise, Luton, on 15 July last year.
Nathan Mwanje used a garden fork in the attack causing a wound that needed 28 staples, Luton Crown Court was told.
Judge John Bevan QC said he understood the provocation but he had to take such a disgraceful act seriously.
Mr Hind said in an impact statement: "I know it was childish to bare my bum. I honestly believed I was going to be killed."
Mwanje, 26, pleaded not guilty to wounding with intent but was convicted by the jury.
Judge Bevan said: "You were provoked by him mooning at you but you simply lost your temper.
"You attacked him with a garden fork which has been a life changing experience. It is disgraceful what you did, and I have to take a serious view of this."
Cameron Crowe, prosecuting, said Mr Hind and his uncle Jeremy had parked their van in Russell Rise because Jay Jay wanted to finish smoking a joint.
'Exposed his buttocks'
Mwanje began to take photos of the van and occupants with his mobile phone as he was concerned about attacks of vandalism, the court heard.
"An argument developed and flippantly and childishly Mr Hind exposed his buttocks," he said.
"The defendant picked up a long garden fork and jumped over the fence and began thrusting the fork at the man's chest.
"The victim suffered multiple injuries to his hands. He tried to run back to the van but was chased.
"Mwanje struck Mr Hind on the top of his head with the fork."
Robert English, defending Mwanje, said: "This was wildly out of character and not premeditated."