A man wailed “What have I done” after crushing his girlfriend’s toddler to death with his car seat, a court has heard.
Stephen Waterson, 25, called 999 after three-year-old Alfie Lamb collapsed in the back of his Audi convertible on the journey home from a shopping trip.
He left the scene before paramedics arrived and burst into tears in his flat in Croydon, south London, the Old Bailey was told.
His stepbrother Marcus Lamb, 22, who had been behind the wheel, told jurors: “He started bawling out tears, saying something like ‘what have I done’.”
Waterson is on trial for Alfie’s manslaughter alongside the boy’s mother Adrian Hoare, 23, who allegedly did nothing to stop it.
Alfie was allegedly squashed in the rear footwell of the blue Audi A4 when Waterson twice reversed his front passenger seat because he was annoyed at the boy’s noise.
There were four adults and two young children in the car on the journey back to Croydon from Sutton, south London, on the afternoon of February 1 last year.
Giving evidence from behind a screen, Mr Lamb described the trip to buy birthday presents.
Prosecutor Duncan Atkinson QC asked: “How was Adrian treating Alfie when they were shopping?”
Mr Lamb replied: “Quite bad, to be honest. If he tripped up she would drag him up.”
The witness added she was also “screaming at him”.
During the journey home, Mr Lamb said he kept his eyes on the road but heard Alfie “screaming”.
He said: “I think I heard him say ‘mummy’ – just heard people telling him to shut up. Stephen – and Adrian told him once as well. Alfie did not be quiet and kept screaming.”
Hoare also “slapped Alfie around the head” in a bid to stop the noise, Mr Lamb said.
A short time before they reached Adams Way in Croydon, Alfie went quiet, the court heard.
Describing what happened when they arrived, Mr Lamb said: “He (Waterson) put his chair forward and asked Alfie to wake up and he did not respond so picked him up and he were not responding, and Adrian got out of the car.
“He kept telling Alfie to ‘wake up, wake up, wake up’, so he shook him a little bit to try to get him to respond.
“Adrian got out of the car and she started breaking down because Alfie was unresponsive.
“Stephen called the ambulance. Stephen started speaking to them and he started CPR. Then he stopped giving CPR and passed the phone to me, and the ambulance man on the line was telling me how to do CPR because I never done it in my life.”
During the desperate bid to save Alfie, Waterson walked off and went into his flat as Hoare was comforted by her friend Emilie Williams, who held the other young child in her arms.
The witness said he had been disqualified from driving but Waterson “forced” him to get behind the wheel that day with “threats”.
Both children had been put into the rear footwell after Waterson allegedly refused to allow child seats.
Mr Lamb told the court he knew Hoare through his uncle Richard, Alfie’s father, and was dating Miss Williams, 19, who was also in the car.
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.