Leonard Nattrass-Berquist is one of only two people who know what happened inside unit one at Ascot Epsom motel where a man was fatally bashed.
He was only 17 years-old when he says he was taken to the motel by 54 year-old Ihaia Gillman-Harris, who he had met on Auckland's Queen St just a week before.
He and his friend Beauen Wallace-Loretz have denied charges of murdering Mr Gillman-Harris and are on trial at the High Court in Auckland.
Giving evidence in his own defence today, he told the court he was sexually assaulted by Mr Gillman-Harris before a struggle ensued.
He said his friend, Mr Wallace-Loretz, came to his rescue and used a bottle to hit Mr Gillman-Harris over the head twice.
The night had started with a drinking session.
Mr Nattrass-Berquist said Mr Gillman-Harris gave the teenagers a box of pre-mix bourbon and the pair drank the entire pack of 18 cans in the early hours of 27 December, 2014.
He said during the drinking session, Mr Gillman-Harris approached Mr Wallace-Loretz and offered him $1000 to perform a sex act but his friend refused.
He said Mr Gillman-Harris drove them all across Auckland.
Text messages sent between the two teenagers during the drive talked of rolling Mr Gillman-Harris. One of the messages said "take him motel and we'll smoke him there".
Mr Nattrass-Berquist said he was just saying what came into his head and it was out of character.
He said Mr Gillman-Harris eventually took them to the Epsom Ascot motel.
The teenager, now 18-years-old, said he hoped to sleep after drinking all night.
But he said once inside the unit, Mr Gillman-Harris put a bottle of alcohol on the table and brought out his laptop.
He said while Mr Wallace-Loretz was in the toilet, Mr Gillman Harris began playing a pornography movie on his laptop.
Mr Nattrass-Berquist said he responded by slamming the laptop lid closed.
He said that made Mr Gillman-Harris angry. He described the 118kg man's eyes going black and said he "squared up" and told him that the two teenagers had been dicking him around for long enough and it was time they paid.
He said Mr Gillman-Harris threw him on to the bed and sexually assaulted him before grabbing him around the neck. The teenager said everything went blank and numb.
Mr Nattrass-Berquist said his friend Mr Wallace-Loretz came to his rescue and there was a struggle as the two teenagers tried to overpower the older man.
Eventually, as Mr Gillman-Harris had his hands around Mr Nattrass-Berquist's neck, Mr Wallace-Loretz picked up the bottle of alcohol. He said Mr Wallace-Loretz hit Mr Gillman-Harris over the head twice with the bottle.
He said Mr Gillman-Harris was still conscious and apologised for what had happened.
Mr Nattrass-Berquist said he was grateful for what his friend had done and he had feared for his life.
The two teenagers left the motel in Mr Gillman-Harris' Rangerover which was later abandoned in the streets of Pakuranga.
The following day when the pair heard Mr Gillman-Harris had died, he said they cried and felt terribe for what had happened.
The cross-examination by Mr Nattrass-Berquist began late this afternoon and will continue tomorrow.