He said he had earlier been introduced to the prominent Kiwi by the entertainer.
However, one day after eating some uncooked meat at the home he fell ill and "started feeling nauseous".
"I began vomiting," he said.
He retired to his bedroom to recover before resting in another room.
"Once I was in bed ... the door opened," he said.
"It was [the businessman] and he was standing there ... He was wearing nothing."
The young man said the businessman asked him what he was doing.
"I said, 'I was trying to have a sleep, I'm in a lot of pain'. He then told me to 'leave that room' and said 'it was only for guests'.
"I respected his wishes and then he said, 'come into my room' and then said, 'come into my bed'.
"I felt I just wanted to have a sleep, I just wanted my stomach to ease off," the young man said, adding that he left for his own bedroom.
But the businessman would return, the young man said.
"He then came onto the side of the bed where he was in between the wall and myself. He began spooning me," he said, visibly shaken when recalling the alleged incident.
"By that time my stomach was quite sore ... I told him I didn't want him here. He told me, 'everything was going to be okay'. He started putting his hands down my pants and playing with my penis."
The young man said he tried to reach his phone and call a friend - who was also staying at the home - for help.
"For a moment I thought that I should just lie there and just let him do it to me - that it would be over soon - but I just couldn't, so I just kept trying to call [my friend], I tried to call him so he would hear," the second complainant said.
"After [my friend] wasn't coming, I remember lying there for a bit grabbing my stomach trying to gather as much strength as I could, trying to gather myself. It was a few minutes, [that the businessman] was playing with my penis."
The young man told the court he then shoved the prominent Kiwi with his elbow and punched him.
"Don't punch, let me embrace you, let me hold you," the businessman allegedly told the young man fleeing the room.
"I ran to [my friend's] room and started banging on his door for help," the second complainant said.
He then recalled "sitting on the floor, curled into a ball" and said to his friend: "[The businessman] is in there, [the businessman] is next door."
After the young man's friend talked to the businessman for a few moments he took the second complainant - who was vomiting again - to the hospital, the court heard.
The young man earlier said when he saw the businessman standing naked in the doorway he felt it was "troubling, terrifying".
The businessman, he explained, had given him "reason to be afraid".
"The first few days I was staying at [the businessman's house] he brought me up to a room that was an extension of his bedroom," the young man said.
"He pulled my pants down and was just staring. I pulled them back up and left."
On another occasion the businessman discussed the prospect of the young man doing "nude photographs in an artistic way", the court heard.
"I wasn't open to the suggestion as I didn't feel comfortable, so he suggested to have a look at my body to see if it would be a good fit," the second complainant said.
Earlier in the trial, the court heard from the first complainant.
At the time of the alleged incident in 2008, the young man said he contacted the businessman to ask for financial support for a project.
The pair met at the prominent New Zealander's lavish home and drank gin and tonic before dinner, and wine.
However, the businessman then took the man for a tour of his home, the complainant said.
As the tour continued, the complainant explained, he began to feel dizzy and unwell.
"He came up behind me and put his hand on my ass and squeezed it and said, 'god, you've got such a sweet ass', and kissed the back of my neck and said, 'why does there have to be a [partner]," the young man said.
"I was so shocked that I just stopped and stood very still."
In a letter to police, the businessman said of the first complainant's claims: "I deny the allegations ... Completely untrue."
All three defendants had their interim name suppression revoked earlier this week by Judge Russell Collins after a successful legal challenge by the Herald and Stuff. But their names will remain secret after lawyers for the accused indicated an appeal to the High Court.
The jury trial, which is set for four weeks, continues.
