The pained words of an 11-year-old boy who saw his father kill his mother.

— With AAP.

Warning: This post deals with domestic violence and could be triggering to some readers.

One of two young Western Sydney boys who saw their father murder their mother by shutting her in a burning room has told a court “there is no way” he will ever forgive his father.

In July, the boy’s 45-year-old father, who cannot be named, was found guilty of murdering his wife by using petrol to light a fire and trap her in her bedroom.

The attack came a week after the boy’s mother told her husband she was leaving him after meeting another man on a dating site two weeks before her death.

Now, in a victim impact statement presented to the NSW Supreme Court on Friday morning, the man’s eldest son has told the court of his pain, saying that he hates his father and he doesn’t want him to get out of jail.

“He burnt my mum right in front of my eyes and nearly killed me,” the now 11-year-old boy wrote in a victim impact statement tendered at the sentence hearing.

“I do not want him to know anything about me.”

The young boy, who was nine at the time, wrote that it was two years since he had been separated from everybody.

“I’m a human. I have emotions as well,” he wrote.

His father had denied using petrol to ignite the deadly fire in the early hours after fighting with his wife over her use of the messaging application Viber.

The then nine-year-old boy told police he woke to hear his mother screaming his name and saw a burning blanket near her bedroom door.

But when the boy and his younger brother tried to open the door, their father pushed them away and took them outside.

The boy also wrote that he wanted his relatives to come to Australia from overseas as soon as possible, so that he can have a “peaceful life” with them.

“I need my grandma and aunty to come here because I am tired of being alone,” he said.

“Personally, my brother has been pouring all his feelings on to me because he has no one else to release his feelings on.

“So if my grandma comes both of us will be very happy.”

On Friday, crown prosecutor Chris Maxwell QC argued the man should spend the rest of his life behind bars.

He stated that the crime was about dominance, possession and jealousy, had been planned and done in the presence of their sons.

But defence barrister Carolyn Davenport SC submitted the case was not one that called for life and noted that domestic killings often, by their nature, were done in the presence of children of the relationship.

The man will be sentenced on November 2.