A woman who claimed to be terrified when she witnessed her boyfriend being murdered was actually his killer, jurors have heard.
Mark Shaw was tied up, beaten, bitten, gagged, attacked with weapons and stabbed to death at his home in Grange Villa, near Chester-le-Street, in December last year.
The 29-year-old suffered multiple injuries across his body in the "sustained" attack, which prosecutors claim was at the hands of his girlfriend, Zoe Warren, 19, and neighbour Keiran Adey, 19.
His body was found, still bound at the ankles, in a bedroom at his Pine Street home.
Warren of Chipchase, Washington, and Adey, of Queen Street, Grange Villa, both deny murder and are being tried by a jury at Newcastle Crown Court.
Warren has told jurors she was at the scene when Mr Shaw was "tortured" and then murdered by her co-accused Adey but denied being part of any violence herself.
She told the court she was "terrified" and "in shock" during the vicious attack on the man she described as her "best friend" who made her "happy".
Adey has now taken his turn in the witness box and has told jurors he took part in the beating of Mr Shaw - but claimed it was Warren who used weapons and stabbed him.
Adey told jurors it was Warren's idea that Mr Shaw should be tied up after the violence erupted at the house.
He told the court: "Zoe just flipped.
"She said something about him pinching my last money' and started smashing upstairs up, hoying stuff around , slamming doors.
"Nothing provoked her, she just started going off it."
Adey said Warren lashed out at Mr Shaw with a pool cue "quite a few times" while was tied up and gagged with his own belt in a bedroom.
He said Warren then picked up a knife and "stuck it in Mark's back".
Adey added: "Mark made a noise of pain and she pulled it out and hoyed it on the floor."
Adey said he had not realised Mr Shaw was dead when he left him in the house.
Warren and Adey both deny murder.
Warren also denies a charge of intimidation in relation to an angry letter she allegedly sent to a man she started a new relationship with just weeks after the killing.
Prosecutors claim she confessed to the man that she was part of the killing, then "turned on" him after he became a witness in the case.
The trial continues.