A teenage boy claims his stepmother often spanked him and his brother with a metal spatula until their buttocks bled.
But the woman's lawyer says the alleged years of beatings never happened.
The allegations are at the centre of a judge-alone trial before Judge Tom Gilbert which began in the Christchurch District Court today.
The woman denies 12 charges of assaulting the children with a weapon, as well as a charge of assaulting her husband with a steak knife, and assault on a family member.
The first witness, now aged 16, said he had been beaten regularly with a metal spatula or a wooden spoon since he was about 6 years old, along with his younger brother.
He said the boys would be beaten until their buttocks bled and were intimidated by their stepmother because she said she would make things worse for them.
The older boy said they were told to pull down their pants for the beatings which happened for a number of reasons, including making a mess, having a water fight, failing to eat their school lunch, or returning to school when they could not find their stepmother at home.
One of the boys told of another incident during lockdown in 2020, when he said the woman had attacked his father with a steak knife during dinner, knocking his plate and sending it flying and then stabbing at his face with a steak knife.
"He would probably have lost an eye if he had not been wearing glasses," the boy told the court. His father had scratches on his nose and around his eye, and a scratch on his glasses.
The younger brother also told the judge of many beatings by their stepmother.
"She was not a very nice person. But when dad came home she was a completely different person," he said.
Defence counsel Craig Ruane questioned the older boy about why he had waited so long - well after the stepmother left the home - before he told his own mother about the beatings.
"We thought she would make it worse for us if we told dad."
When the father saw scabs on his buttocks, the stepmother said it was a skin reaction to a milk allergy. He would put his washing into a washing basket, and no one had noticed blood on his underwear or shorts.
"Neither me nor my brother liked her at all during the time they were married," he said.
He said she had ended up blaming him and his brother for everything, and favouring her own son.
Ruane put it to the witness that none of the spankings happened and that it had all been made up to support his father in his separation from the stepmother.
"This was a way of getting back at her after she left," he said.
The teenager rejected that.