A psychologist’s alleged threat to kill a teen patient if he revealed a sexual assault led to the youth staying silent for years, a jury has heard.

The 59-year-old former clinical psychologist, who cannot be legally named, is accused of raping and molesting a 15-year-old boy in his office on the NSW north coast in mid-2017.

The teen, who attended two counselling sessions, did not tell his parents about the alleged incident immediately after because he was fearful, jurors at a District Court trial were told on Thursday.

Know the news with the 7NEWS app: Download today

“He told me if I told anyone he’d kill me, so I was scared for my life to say a single word about it,” he said under questioning by crown prosecutor Steve Wilkinson.

The boy believed the death threat because the psychologist had all his details, keeping the alleged incident secret for years.

He only told his parents and made a statement to police after hearing about the psychologist’s arrest.

“I knew something f***ing happened with him,” the boy’s mother allegedly said after her son revealed the claimed sexual assault.

The complainant told jurors he stopped going to school after seeing the psychologist, withdrawing to his room.

He slept during the day and couldn’t sleep properly at night, having nightmares where he relived being raped, he told the jury.

Under cross-examination by defence barrister Anita Betts, the alleged victim admitted he had assaulted a fellow student about the time he attended counselling.

He had been suspended from school multiple times, the court was told.

However, the former-patient denied he was angry at the time he saw the psychologist.

“I was easily frustrated and agitated but I was not constantly angry,” he said.

The psychologist has pleaded not guilty to one count of indecent assault and one count of sexual intercourse without consent, both relating to allegations with a boy under 16 years old.

He has denied that anything untoward took place.

Prosecutors have told jurors about claimed admissions by the 59-year-old of separate sexual abuse of a number of other former patients.

These prove he had a tendency to act in a certain way, Wilkinson said on Wednesday.

The psychologist denies this, saying he was coerced or induced into making the admissions by his former lawyers.

The trial continues.

If you or someone you know is impacted by sexual assault, domestic or family violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au.

In an emergency, call 000.