Son says dad threatened mum: Vic court

A Melbourne man on trial for brutally murdering his ex-wife made repeated threats to kill her and claimed she had ruined the family, their son says.

"He'd say, 'Your mum's done this to us, she's destroyed this family, I'm going to kill her'," Daniel Paulino, 26, told a Supreme Court jury on Monday.

Fernando Manuel Paulino, 55, has pleaded not guilty to murdering his wife of 23 years, Teresa Paulino, 49 in 2013.

Daniel Paulino said his dad had threatened to kill his mum, or himself, at least five to 10 times.

At the time she was killed, Teresa Paulino had started family court proceedings and had an intervention order out against her former husband.

He was increasingly angry at the mounting legal bills and feared he would lose the family home and possibly two factories, the jury heard.

"He said that she'll pay for this one way or another," Daniel Paulino said.

Younger son, Luke Paulino, 24, testified his father would call their mum "slut" and "bitch" interchangeably.

He also tried to show his sons a pornographic video on his phone, claiming it was their mother performing oral sex on a man.

"He said look at your Mum. He just placed it in front of me as I was eating," Luke Paulino said.

"I was quite shocked. It was just clearly not Mum."

Daniel Paulino said his parents often argued throughout their marriage and his father believed his mother had cheated on him. After the split, his mother left the family home "terrified".

The jury heard that on the night of her death, Daniel and Luke shared dinner with their mother at their aunt's house.

But afterwards, when Daniel returned to the Taylors Lakes house he and his brother shared with their father, the TVs and lights were on but his father and the car were missing.

He said he rang his father a number of times to see where he was but the phone rang out.

Daniel said when his father returned his call late that night, his voice sounded strange.

"It sounded like he was in an adrenaline or drunken state," he said. "He wasn't himself."

The trial continues on Tuesday.