Warning: Sexual content and themes.

On a stormy night several years ago an accomplished Kiwi musician says a man possibly drugged and sexually violated him in an Auckland home, a court has heard.

The young musician, who cannot be identified by the Herald for legal reasons, had visited the man's house for dinner in 2013.

"It became a bit spooky, very dark," the musician recalled of the "horrifically stormy" evening while giving evidence, setting the scene for jurors.

"It almost looks like a haunted mansion by Walt Disney."

As the heavy rain continued outside, the pair had a glass of wine and began the evening by talking about the musician's recent studies in North America.

The house with a fire crackling in the corner reminded him of the murder mystery board game Cluedo, while classical music was also blaring from the sound system, the musician said.

However, what allegedly occurred next is why the accused man now faces and denies charges of sexual violation and attempted sexual violation in the High Court at Auckland.

The accused man, who has interim name suppression and other court orders protecting their identity, began to steer the conversation towards topics of a personal nature and sexuality, prosecutor Simon Foote QC said during his opening address on day one of the trial.

The man asked the musician if he had anyone to "teach or educate him in a sexual sense", the court heard.

"'Do you have anyone to teach you,' were his words," the musician said.

"I'm sorry, I'm not sure what your intentions are but mine are purely just friendship," he said he told the man.

The musician said the man also placed his hand on their shoulder and encouraged him to relax, before offering the use of one of the guest rooms for the night.

"'I've got oils upstairs, I can give you a massage'," the man allegedly said.

Foote said: "At this stage, they were on their third glass of wine."

Before retiring for the evening, however, the man suggested the pair watch some television together, which led to the man leaning in for a kiss, the jury was told.

The musician, shocked and unsure about what to do in the moment, kissed him back, Foote said.

Suddenly, Foote continued, the musician felt woozy and unwell, later vomiting twice in quick succession in the bathroom and their vision became "blurry".

"I thought it could've been a potential drugging in the wine," the musician speculated, adding the man had also offered him a milky glass of water.

"[He] offered me a short glass, with what I thought was aspirin."

During the night, Foote alleges, the man sexually violated the musician and attempted to again a second time.

"[The musician] said he felt like a puppet or child-like," Foote said. "Like he was in a movie."

"I was feeling so unwell," the musician recalled during his evidence. "I was just lying there, basically, hoping it would stop. I just didn't want it at all."

The following day he awoke naked in the man's bed.

"I could feel his eyes looking at me," the musician said as he left the home after declining breakfast. "I wasn't sure if I was okay to drive."

Upon returning home, the musician said he sat in the shower and washed his mouth out with soap in an effort to scrub away the taste of the night.

Foote told the jurors the musician "said nothing, did nothing" but several years later felt compelled to make a complaint with the police for reasons which the Herald cannot report due to a court order.

The accused man's lawyer, David Jones QC, told the jury in a brief opening statement the case involved an issue of consent between his client and the musician.

"You've got to have something that happens physically and you've got to have a guilty mind," Jones said, explaining the criteria for the Crown's charges to be proven.

"You've got to know it's wrong ... you've got to know there is no consent."

The trial before a jury and presided over by Justice Mary Peters continues and is expected to last seven days.