A TEENAGER who shared a sordid relationship with a married couple has testified that the doctors waxed her legs and showered with her before the wife allegedly bludgeoned her husband to death with a hammer.

The 19-year-old, who cannot be named, was 17 at the time of the three-way relationship in 2014.

On Tuesday, the teen gave evidence in the Supreme Court of Western Australia murder trial in Geraldton of Chamari Liyanage.

Dr Liyanage is accused of killing her husband and fellow doctor Dinendra Athukorala in their Geraldton home in June 2014.

Dr Liyanage allegedly bludgeoned her husband to death with a hammer, fearing he would reveal they were having sex with a teenager.

Prosecutors claim Dr Liyanage was fed up with her husband’s sexual demands, which included the couple having sex with other women, and was also concerned about the effect the couple’s relationship with the 17-year-old would have on her career.

“It got to a stage that she was no longer prepared to put up with his behaviour,” prosecutor Nick Cogan said, the West Australian reported.

But the accused woman’s defence argues she was a “trapped and battered woman”.

Dr Liyanage told police her husband was physically violent, forced her to engage in sexual acts and controlled her movements and finances.

The teenager told jurors she met the Sri Lankan pair at a dinner party in 2014 and had several encounters with them in their home.

She said the couple was happy and “always smiling and laughing and affectionate”.

The teen said Dr Athukorala always wanted to take photos and videos and on one occasion Dr Liyanage took her shorts off and ran her hand over her underwear under Dr Athukorala’s direction.

“He was watching the whole time, sometimes recording,” the teen said.

The woman said she then had a shower with Dr Liyanage while Dr Athukorala watched and eventually joined the pair.

“I didn’t feel very comfortable after what happened when Chamari touched me, I was confused and naive, I didn’t feel secured,” she said.

She also testified that Dr Liyanage and Dr Athukorala waxed her legs.

“Chamari started waxing my legs and Din helped,” the woman told the court.

“[Doctor Athukorala] was in the bedroom.

“He was holding a video camera.

“He hugged me from behind and they asked me if I had a boyfriend.”

During the teenage girl’s evidence, Dr Liyanage looked down, sobbed and shook in the dock.

The teenager said in one encounter Dr Athukorala gave her a glass of whisky and wanted to dance, but she woke up the next morning with a bad headache in bed with Dr Liyanage.

She said at one point during the night Dr Athukorala, who knew she was a virgin, was on top of her but his wife tapped him on the shoulder and told him “don’t”.

The teen said at one stage the couple demonstrated sex in front of her.

She said Dr Liyanage always obeyed her husband “with a smile”.

The couple bought the teen clothes and shoes and even a new camera after Dr Athukorala got down on one knee and begged her to accept it.

She said she stopped seeing the couple after Dr Liyanage told her while they were alone in a car she could refuse to take part at any time.

Before then, she felt she couldn’t say no to Dr Athukorala.

“He was too controlling,” she said.

The teen said she considered Dr Liyanage to be a second mother figure and met with her in prison after she was charged.

She said Dr Liyanage apologised for dragging her into this and told her about the abuse she had suffered from her husband.

The jury heard a tearful 10-minute call Dr Liyanage made to triple-0 at 6.11am in June 2014, in which she said she could not remember what had happened.

Officers arrived at the unit in Geraldton, WA, at 6.18am and spoke to Dr Liyanage as she sat in the foetal position by the bed.

Dr Athukorala’s body was lying on the mattress covered in blood, which had splattered over the wall and blinds above him, police said. A pillow was on top of the corpse, they told the court.

“I asked if she knew what had happened,” said Matthew Curley, one of the first officers on the scene. “She said she did not know.”

He said he also saw a mallet or hammer lying on the bed. When asked, a sobbing Dr Liyanage said it belonged to her husband.

Defence lawyer George Giudice said his client was a “sleep-deprived, anxious, trapped and battered woman”. He said she was made to model for her husband in front of a camera, sometimes for hours on end.

Dr Liyanage pleaded not guilty to murdering her husband. The trial, set down for three weeks, continues.