Gurjinder Singh has told the High Court in Auckland he planned to confront his lover's husband about his violence but not stab him.
Today, under cross-examination, he raised his voice as he answered questions about notes passed between him and his former lover Amandeep Kaur.
Gurjinder Singh and Amandeep Kaur are on trial on a charge of murdering Mrs Kaur's husband, Davender Singh.
Davender Singh was found dead in his car in Papatoetoe in August 2014.
Under cross-examination by Mrs Kaur's lawyer Sanjay Patel, Gurjinder Singh agreed there was talk of killing in the notes but they were written by Mrs Kaur who was angry after being beaten by her husband.
Mr Patel suggested Gurjinder Singh was angry after Mrs Kaur had ended the affair.
Gurjinder Singh said Amandeep still wanted to live with him.
Mr Patel also suggested Gurjinder Singh's parents were on their way to New Zealand from India, and he was scared Davender Singh was going to disgrace him by alerting them to the affair.
Mr Patel suggested to Gurjinder Singh that he wanted to get rid of Davender Singh.
Gurjinder Singh said Mr Patel's questions suggested killing someone was simple. He said it would have been easy to just move house away from Davender, rather than killing him.
He said he wanted to confront Davender about his violence towards his wife and re-assure Davender that the affair was over.
Gurjinder Singh said he arrived at the car to find Davender Singh already stabbed.
He said Amandeep Kaur handed a him a bloody hoodie jacket and a cell phone to get rid of.
He told the court it was his sweatshirt but Mrs Kaur took it from his car on the day of the killing. He said he did not know how the blood got on it.
Police later found the knife, a bloody sweatshirt and gloves hidden in Gurjinder Singh's garage.