The mother of a "perfect" five-year-old boy beaten to death by her then-boyfriend said she hopes the killer is never released from prison.
Lilya Breha's son Alex Malcolm died after being battered in a park by Marvyn Iheanacho, who flew into a rage at the little boy for losing a trainer.
Iheanacho was jailed for life with a minimum term of 18 years for the attack against the young boy, who Judge Mark Dennis QC described as "completely defenceless" in the face of the 39-year-old's "brute force".
Speaking after the sentencing at Woolwich Crown Court, Alex's mother said she was heartbroken by what happened.
In a tearful interview she said: "He (Alex) was bubbly. He was just perfect you know, he was a really, really special little boy.
"He was shy, he was so shy, and very polite. He would always say 'Mummy thank you' and 'I love you mummy'."
Witnesses heard a child's fearful voice saying "sorry", loud banging and a man screaming about the loss of a shoe during the attack in Mountsfield Park in Catford, south-east London, the trial heard.
Alex suffered fatal head and stomach injuries and died in hospital two days after the attack last year.
One of his trainers was later found in the play area by police.
Iheanacho, from Hounslow, west London, has a "deeply entrenched character flaw", Judge Dennis said, adding: "One that leads you to overreact and lose your temper."
The killer has a string of previous convictions for violent offences, including attacks on ex-partners and robbery.
The judge said Iheanacho had given fake and misleading accounts to paramedics, hospital staff and police.
"All this to protect yourself and cover up what you had done," he said.
Ms Breha, 30, described Iheanacho as a "good liar" and pathetic.
Recalling how she met him through a friend after he left prison, she said he had convinced her he was innocent and a good person.
She said: "When I think about it now to be honest, I feel like it was all such a big lie and he just pretended to be a good guy pretty well.
"I think he hid this (a temper) as well pretty well, until the point he just probably snapped."
Asked what she hoped for at the sentencing, she said: "That he never come out again to be honest. I don't feel that he should be out in the first place, after everything he did before."
She said she is constantly reminded of Alex since his death, adding: "Everywhere I go, everywhere I look I see him, climbing, jumping, screaming my name. It has broken my heart."
Alex's head, neck and body were covered with bruises after the attack on November 20 last year.
Iheanacho carried the unconscious boy to a minicab office and took him to Ms Breha's flat, while the nearest hospital was just a five-minute walk away.
He then attacked Ms Breha when she tried to call an ambulance, but she managed to grab the phone after noticing her son was getting cold, his face had turned blue and he had stopped breathing.
She said she thought she might die when Iheanacho started strangling her. She said: "I couldn't say anything. And those moments I knew that is what it feels like to die because my eyes start rolling."
He eventually released her from his grip and she was able to call the ambulance.
Doctors at Lewisham Hospital tried to resuscitate Alex, but a CT scan showed he was suffering from severe brain swelling, and he was transferred to King's College Hospital.
He was pronounced dead on November 22 after an unsuccessful operation.
It emerged during the trial that Iheanacho had phoned Ms Breha from prison to pressure her to back him up in court.
"There have been problems with witness interference. The defendant has phoned the mother of the deceased," said prosecutor Eleanor Laws QC.
"We would say pressure is being exerted on the mother of the deceased, with the defendant pressing upon her his defence of accident."
Ms Breha, who moved to the UK from Ukraine a decade ago, said she feels lost since the murder.
She said: "I feel like for me it is like I have to start everything from the beginning. All this 10 years I've been in this country, it's gone literally. He took everything away from me. I don't know which way to go."
Looking to the future, Ms Breha told how she wants to try to give support to other parents whose children have been murdered, perhaps through charity work.
She said: "Hopefully I can be able to help somebody else not to make the same mistakes I did."
A victim impact statement from Alex's father Leroy Malcolm, read out in court, said: "He was a lovely and energetic and playful little boy.
"I will never forget seeing him in his hospital bed fighting for his life. That image will stay with me forever."
He added that it has been very difficult to keep his emotions in check.
"Just thinking about what's happened and trying to put words on paper is tearing me apart."
Iheanacho was sentenced to 18 years but, due to time served on remand, the judge said he would serve at least 17 years and 119 days.