Within days of the disappearance of young Sydney man Matthew Leveson, his partner Michael Atkins had invited a 20-year-old former lover to the annual Sleaze Ball, the coroner's court has heard.
A man going under the pseudonym Anthony Rogers told the ongoing inquest into Mr Leveson's death that on September 29, 2007 - six days after Mr Leveson was last seen - he received a text message from Mr Atkins.
In it, Mr Atkins, then 44, told Mr Rogers that he had a "spare ticket" to the ball and asked if he wanted to come along.
Mr Rogers told the inquest on Tuesday that, while he had had a sexual encounter with Mr Atkins before, he had been surprised by the invitation because he believed the older man was still seeing Mr Leveson.
The surprise was compounded when Mr Atkins told him Mr Leveson was coming separately "with some friends" and that they would all meet up later in the night.
"[We had] a conversation along the lines of 'why aren't you going together?' It was confusing to me, I would go together if I was with someone," Mr Rogers told the inquest.
"He said there wasn't anything wrong and that they weren't fighting."
The court heard that this was far from the truth.
By this time, Mr Leveson's family and friends had been desperately trying to find him - calling and messaging everyone they knew, speaking with the police, and searching the area around the young man's work and home.
Mr Rogers, completely unaware that Mr Leveson was missing, agreed to go to the ball.
He said that when they arrived, Mr Atkins offered him a dose of the drug 'GHB' contained in a small plastic fish of the type sushi restaurants often used to distribute soy sauce.
He told the inquest that he drank the entire vial, resulting in an overdose that forced him to the ball's medical tent where he stayed until the next morning.
Mr Rogers said he only found the next day that Mr Leveson was missing when a friend told him it was "strange" that Atkins had invited him to the event.
"It was a big discomfort for me - that this had happened and that I had no idea about it," Mr Rogers said.
Mr Leveson, 20, was last seen leaving ARQ in the early hours of September 23, 2007, with Mr Atkins.
After Mr Leveson was reported missing, police found his abandoned car with a Bunnings Warehouse receipt for a mattock and gaffer tape inside.
Mr Atkins' fingerprint was on the receipt, the inquest has heard.
CCTV footage from the hardware store showed Mr Atkins buying the items about midday on September 23, the inquest has heard, but he has always denied involvement in Mr Leveson's disappearance.
Mr Atkins was arrested and charged with murdering Mr Leveson, but was acquitted by a jury in October 2009.
Mr Leveson's family requested the inquest be held to get some answers about what happened to him, and where his body is.
Earlier on Tuesday, the inquest heard evidence from a woman going under the pseudonym Jane Brown, who had been in a relationship with Mr Atkins for seven years before he met Mr Leveson.
Ms Brown said that she went to visit Mr Atkins in jail after seeing a story about his arrest in The St George and Sutherland Shire Leader.
"He looked at me straight and said 'I have nothing to worry about - I've done nothing wrong'," Ms Brown said.
The inquest continues.
