Chris Dawson's former family babysitter has told a murder trial the former rugby league player used to give his wife alcoholic drinks so she would sleep while he cheated on her.
On Wednesday, Mr Dawson's murder trial heard evidence from the teenage babysitter he had started a sexual "relationship" with before his wife Lynette vanished from their Sydney home 40 years ago.
Mr Dawson is accused of murdering Lynette Dawson in January 1982 and disposing of her body, before making a missing person's report a month later.
The family's former babysitter, who cannot be identified, was 16 when Mr Dawson began teaching her Year 11 physical education class at a Northern Beaches high school.
The Crown case against Mr Dawson is that he was motivated to kill his wife as he wanted to enjoy an "unfettered relationship" with the student.
He has pleaded not guilty.
The former babysitter told the judge-only trial Mr Dawson invited her to move into his family home in Bayview after she confided in him about her step-father's violent outbursts at her place.
She said Mr Dawson offered to let her live with him, his wife and their two young daughters in October 1980 so she could complete her high school certificate in a calm environment.
The babysitter told the court that, once she was living with the couple, she noticed Mr Dawson was very "distant" with his wife and made her alcoholic drinks at night that would make her fall asleep.
"She would fall asleep, sometimes in the chair, sometimes she would excuse herself to go to bed," the woman told the court.
"What happened after she fell asleep?" Crown prosecutor Craig Everson SC asked.
"Chris would want me to have sex with him," she answered.
The woman said she would agree and they would do so in the bedroom she was staying in at the time.
Mr Dawson's lawyers have told the court the former rugby league player and his wife were having marital problems but that he never wanted to "get rid of her" and she left of her own accord in January 1982.
The former babysitter said during her time living with the couple, Mr Dawson would often sing "cruel" songs about his wife, inferring that she was unattractive.
"He used to call her fatso," she said.
"He didn't call her Lyn, he called her fatso and laughed about it."
Mr Dawson, who is now 73, would often give the then-teenager driving lessons as a way to spend more time together, the woman told the court.
She said the first time he kissed her was while they sat in the carpark at Dee Why Beach.
The court was shown love notes the prosecution say Mr Dawson left in the woman's school backpack, including a card signed, "Love Always, God".
"He would have disguised himself as it was 1980 and I was 16 so that's what he called himself," she told the court.
The woman, referred to as JC in court, said the last time she saw Ms Dawson was in 1981 when she confronted the teenager about "taking liberties" with her husband.
Mr Dawson married JC in 1984 but the pair separated in 1990.
The court also heard evidence from Ms Dawson's sister-in-law Merilyn Simms, who said the babysitter told her in 1990 that Mr Dawson had considered hiring a hit man to kill his wife. Mr Dawson rejects this claim.
Ms Dawson's remains have never been found and none of her family, except for Mr Dawson, say they have heard from her since January 8, 1982.
Mr Dawson claims she contacted him several times after she disappeared.
Editor's note May 20, 2022: Parts of the headline and copy have been amended to more accurately reflect the reality of JC and the accused's situation.
