A court has heard a man said this to his 12-year-old daughter after he had sexually assaulted her at their Bankstown home in Sydney's west.

The man, who cannot be named for legal reasons, is accused of twice sexually assaulting his daughter after having an argument with his wife and locking her outside, the NSW District Court heard on Tuesday.

Crown prosecutor Brian Rowe told the jury that earlier on the night of March 11, 2015, the accused had told his wife that he had a girlfriend overseas.

When the pair got into an argument the man allegedly said, "Today I'm going to kill you."

When the mother ran off from her husband he locked the gate of their property so she could not get back in.

The court heard the father then went into his little girl's bedroom and sexually assaulted her.

When she started crying and kicked at him he allegedly said, "Oh do you love me or don't you?"

He told her to go out to a back room at the property and sexually assaulted her again.

The mother later told police that while she was locked outside she could hear her daughter crying.

When the mother finally got inside the father allegedly grabbed her, pulled her hair and threatened to kill her.

Defence barrister Bernard Brassil told the jury his client was not a nice person but that he was innocent.

"On this night he was more than distinctly unpleasant, in fact he admits that he was intimidating his wife, he admits that. But he says he did not touch his daughter," Mr Brassil said.

"There is a lot more to see," he said at the end of his opening address.

The father has pleaded guilty to one intimidation charge regarding his wife.

But he has pleaded not guilty to 11 further charges including two counts of sexual intercourse with a child aged under 14, two counts of indecent assault and three counts of assault.

The trial continues before Judge Andrew Haesler.