A woman accused of murder told a jury of the moment she saw a former lover stab the mother of his children.
Julie Wass is jointly charged with Torbjorn, also known as Ian, Kettlewell with the murder of his partner Kelly Franklin.
Ms Franklin, 29, was stabbed more than 30 times by Kettlewell following a confrontation in Oxford Road, Hartlepool.
A jury at Teesside Crown Court heard Wass had driven Kettlewell from his home in Oval Grange, Hartlepool, to the area where the stabbing took place.
"I did have an affair with Ian but that was only for a couple of months in 2017," said Ms Wass.
"We remained friends, and I would often give him lifts, take him where he wanted to go.
"On this evening he said he wanted to go to Catcote Road shops."
Wass said that after dropping off Kettlewell she next saw him knocking on the door of Ms Franklin's house, which was next to her house in Kipling Street.
"There was no answer," said Ms Wass. "I told Ian to get into the car and I would take him home.
"He got into the car, but after a short distance there were roadworks which mean't I had to slow down and Ian jumped out.
"I drove towards Oxford Road to visit my daughter when I saw Ian and Kelly in the street.
"They were arguing, he had her against a lamp post, he had hold of her left shoulder by his right hand.
"I stopped the car and asked what he was doing, I told him to get in the car because I wanted to get him away from Kelly.
"It was then that I saw a silver flash in his left hand, he was stabbing her in the chest, she was standing up.
"He took the knife in and out a few times."
Ms Wass said she drove off and stopped nearby to be sick.
"Ian appeared and jumped into the car," she added. "He told me to drive, to get him away.
"I did drive, I was shocked and scared.
"Ian sniggered and laughed, he told me I had family so I knew what it was like."
The jury heard earlier Ms Wass is accused of murder by what lawyers call a 'secondary party'.
She is guilty if the jury is satisfied she knew Kettlewell intended Ms Franklin serious harm and she had assisted him.
Wass told the jury she admitted assisting an offender, but she did not know Kettlewell intended to harm Ms Franklin.
"When I picked him up I thought he wanted a lift to the shops," she said. "I had given him lifts many times before.
"I never saw a knife, I didn't intent to help him assault her.
"I did not intend she should suffer serious harm."
Kettlewell, 30, of Oval Grange, Hartlepool, denies murder on August 3.
Wass, 48, of Kipling Road, Hartlepool, denies murder.
She admits assisting an offender.
The case continued.