It was August 11, 1997, and Steven Fesus was "fuming" as the couple left a friend's house.

This was also the last time Mrs Fesus was seen alive, the NSW Supreme Court heard on Tuesday.

A little more than a month later, Mrs Fesus' body was found in a shallow grave at Seven Mile Beach at Gerroa. 

Fesus is now standing trial for her strangulation murder. He has pleaded not guilty.

In his opening address, Crown Prosecutor Greg Smith SC also explained that Mrs Fesus had threatened to leave her security guard husband as their short marriage began to crumble.

"I've had enough, I'm leaving him," the mother-of-two told a friend.

Mr Smith said Mr Fesus reported his wife missing at Warilla police station two days after she disappeared.

He was accompanied by Kerry Smith, a work colleague that Mrs Fesus believed her husband was having an affair with.

Mr Smith said evidence would reveal Mr Fesus "became intimate" with Ms Smith in a car park later that same day, and had also tried to claim the sole parent pension two weeks after wife had disappeared.

He was not able to get a full payment because Mrs Fesus had not been found.

"The accused's income was significantly reduced because the deceased had not been found," Mr Smith said.

"The accused had a financial motive for the deceased's body to be located."

In the days before Mrs Fesus body was found, a witness allegedly saw the accused driving a Red Holden Commodore in the vicinity of Gerroa camping ground close to where Mrs Fesus had been buried.

On September 14, 1997 an anonymous male caller told police directed them to the area where Mrs Fesus' remains were later uncovered.

The following day, September 15, the accused went to the department of social security to claim his full pension and said his wife had been found deceased - but the body was still being exhumed and had not been formally identified, Mr Smith added.

The court heard how Mr Fesus had confessed to the killing of his wife to a police officer in 2013.

He allegedly said: "I didn't stab her, I didn't bash her, I choked her out."

"I know I strangled her, it was in the lounge room".

Mr Smith outlined how the pair had a tumultuous relationship and several witnesses had seen them "play wrestle" on the floor.

He said Mr Fesus once put his wife in a sleeper or choke hold, in which she lost consciousness.

Mr Fesus' barrister Grant Brady SC told the jury his client was innocent.

"Steve Fesus did not kill his wife. He didn't cause the death of his wife, he didn't bury his wife and he didn't then expose her body. Mr Fesus did not do what he is accused of doing," he said.

Mr Brady said there were numerous facts the Crown relied upon which would be contested.

At this time of Mrs Fesus' disappearance the couple were living together at a rental property at Mount Warrigal, south of Wollongong

The trial continues before Justice Helen Wilson.