A toddler was crushed to death by an electric car seat because his mother's boyfriend wanted to stretch his long legs out in the front, a court has heard.
Three-and-a-half-year-old Alfie Lamb was squashed in the rear footwell of a blue Audi convertible by Stephen Waterson, the Old Bailey was told.
As he cried and made choking noises, his mother, Adrian Hoare, just told Alfie to be quiet, jurors heard.
Hoare, 23 and Waterson, 25, from Croydon, south London, are on trial accused of his manslaughter.
Emilie Williams, 19, was sitting next to Hoare in the back of the car during the ill-fated trip back from shopping in Sutton, south London, on February 1 last year.
In a videoed police interview, Miss Williams said they all went together, with Marcus Lamb, 22, driving.
She said she was forced to put a second youngster in the rear footwell next to Alfie because she was not allowed to take the children's car seat.
Miss Williams said "Alfie was crying so much it sounded like he was choking", but that his mother said he was OK.
"Marcus's chair was right forward and Stephen's chair was right back," she said. "Alfie was kicking the chair, asking him to move it forward."
Waterson said no "because he said he had to stretch his legs right out", Miss Williams said.
"He had enough room but he wanted to stretch them out because his legs are quite long.
"He moved it forward once but only for a few seconds, only a little bit but it gave Alfie more room.
"Adrian just kept telling him to be quiet and they would be home soon. Like 'We will be home soon, shut up'."
Miss Williams said Hoare told her Alfie was only crying because he was "getting himself worked up".
When he went quiet she thought he had gone to sleep, the court heard.
"As we was pulling up, she tried to wake Alfie up. She told him not to be silly. She thought he was just mucking around."
When Waterson took Alfie out of the car, the child was looking "pale" and not moving, the witness said.
Afterwards, Waterson threatened Miss Williams as he tried to persuade her to lie about what happened, jurors were told.
"He was telling me a lot of things. He said he would put me in the boot of the car and get rid of me. He said he would kill me," she said.
Hoare was "going along with it and helping", she added.
Giving evidence via video-link, Miss Williams told the court that Hoare had slapped her cheek outside Asda after Alfie died.
She said: "It was when Stephen's door got kicked down by police. It only left a hand print for about half an hour."
Cross-examining, Tana Adkin QC said that, according to Waterson, some of the shopping was put into the front footwell of the car.
The witness said she could not remember if that was right.
Hoare denies manslaughter, child cruelty and common assault on Miss Williams.
Waterson has pleaded not guilty to manslaughter and intimidation of Mr Lamb.
The couple and Williams have pleaded guilty to conspiring to pervert the course of justice by making false statements to police.