Former Trinity Grammar School teacher Neil Albert Futcher, 69, is on trial in the Downing Centre District Court accused of sexually abusing boys, aged from 12 to 15, between 1974 and the early 1980s.

Mr Futcher has pleaded not guilty to 22 offences against six boys, including eight counts of buggery, which allegedly occurred while he was teaching at Trinity and working as a swimming coach.

Giving evidence on Tuesday, Mr Futcher denied allegations made against him during the course of the trial, including claims that he raped boys in the back of his van and at his family's Drummoyne apartment, masturbated them, told them to give him oral sex or showed them pornography.

When his defence barrister John Galluzzo asked him about a covert recording that captured him telling one of his alleged victims that he had a "weakness", Mr Futcher said he was talking about his "fancy for mature ladies".

"I've always liked the older ladies and when I was a bit predatory I used to go to various wine bars, piano bars, hotels etc. etc. looking for company," Mr Futcher told the court.

"I developed a guilt complex ... There would be photographs of happy families that you didn't see the night before ... It used to gnaw at me."

Mr Futcher, who was recorded apologising to the alleged victim and agreeing that he had shown him pornography in his apartment, said he had taken prescription drugs and alcohol and was "buzzing" at the time.

"In the condition I was in I might have said anything ... the next day I could barely remember the conversation," Mr Futcher said.

The court has previously heard allegations that Mr Futcher, who boarded at Knox Grammar and was previously a teacher at Sydney Grammar School, invited a handful of students on unofficial school camping trips where he showed them pornography, encouraged them to skinny dip and sexually abused them.

Asked if he took porn to the camps, Mr Futcher said: "There was never any pornographic material for any camp I ever ran for any school, anywhere, at any time."

When asked if he had masturbated boys inside a tent, he replied: "Again, incorrect."

Mr Futcher also denied that he had taken an explicit photo of one boy and threatened to show his parents and that on a separate occasion he had gone into a toilet cubicle at a surf life saving club with three boys and he masturbated and had oral sex with them.

In cross examination, Crown prosecutor Giles Tabuteau put to Mr Futcher that he went out of his way to meet the parents of his students because he wanted to win their trust in anticipation that one day their child might make a complaint about his sexual misconduct.

"That's a long bow you're drawing there," Mr Futcher said. He said he was a "friendly, chatty, gregarious person" who liked the company of the parents and wanted to know them better.

The cross examination of Mr Futcher is due to continue on Wednesday.