After Emma Barrett and her lover murdered her ex-boyfriend, she wrote "you're dead, you dead dog" in the concrete shovelled over his body.
According to Barrett's lover, Dean Reginald Fordham, she had earlier written instructions on how to kill her ex-boyfriend, whom she claimed was a hitman with her in his sights.
Fordham, 28, was giving evidence in the NSW Supreme Court on Thursday at the sentencing hearing of Barrett, 22, who pleaded guilty to murdering David Harrison, 24, in June 2007.
Fordham gave chilling details of how he stabbed Mr Harrison after Barrett "came up with all the ideas", later admitting to the judge that he himself was "not too brainy".
He said Barrett told him she feared for her life, and showed Fordham Mr Harrison's "hit list" which included her name.
Fordham said Mr Harrison had told him and others that he was a hitman and once showed him two guns he had in his car boot.
After pleading guilty to the murder, Fordham was sentenced to a minimum of 11 years last month - which included a discount for his willingness to give evidence against Barrett.
The sentencing judge said there was no evidence at all to support the claim the victim was a hitman and the "hit list" appeared to just be a list of names and phone numbers.
Mr Harrison, who was from the small Victorian town of Tatura, was repeatedly stabbed at the home shared by Barrett and Fordham in Muswellbrook in the NSW Hunter Valley.
Fordham said they buried his body in a shallow grave in bush near Greta, later returning with the quick set concrete.
"She wrote a message - you're dead, you dead dog - with a stick," he said.
Barrett cried in the dock as the victim's mother, Jean Harrison, told of the heartache caused by his death.
"Physically and emotionally, I am drained," she said.
"No one knows what I am going through or how much pain I am in.
"I will never forget the people that did this to me.
"I will never be able to trust people like I used to."
Fordham said after Barrett received a threatening text message from Mr Harrison, she told him she wanted to kill him and needed Fordham's help.
"She started writing out all different ways on how to kill him," he said.
She also wrote out a shopping list of what they needed, including gloves, garbage bags and bleach - items which they purchased together.
After Barrett invited their victim to their home, she went out with him so Fordham could "get ready".
On their return, Fordham said he "ran behind him and stabbed him once in the face", before Mr Harrison ran off down the road.
"Emma said: `What are you doing, go and get him'," Fordham said.
After he brought him back, Fordham said he "blacked out" but accepted he repeatedly stabbed him.
Later, Barrett told him Mr Harrison was still alive, and they both stabbed him.
The sentencing submissions will continue on March 26 before Acting Justice Jane Mathews.