Rob Packham, who is charged with the murder of his wife Gill, had expressed unhappiness about his marriage and had hoped to build a future with his mistress, the Western Cape High Court heard on Tuesday.
This was the evidence of the woman who had an extramarital affair with Packham.
"He said he loved his life but he didn't love his wife," the woman said.
She may not be identified in terms of an order issued by the court last year, which considered that she had two minor children.
Dressed in a smart navy-blue suit and white top, she methodically detailed her relationship with the former general manager of cooldrink manufacturer Twizza, since their first meeting in October 2015.
"He told me he was separated from his late wife," she said.
She explained to Judge Elize Steyn that Packham had two phones, one for work and a "burner phone" he used for private correspondence that his family and wife did not know about.
They were still seeing each other until the day his wife went missing on February 22, 2018.
Packham has pleaded not guilty to the murder of his wife and a charge of obstruction of justice.
Her charred remains were found on February 22, in the boot of her burnt-out car at the Diep River train station after the fire was extinguished.
Packham's ex-mistress said he told her he stayed in a flat with his eldest daughter. He informed her on December 15, 2018, he had decided to move back in with his wife.
She said Gill was not aware of their relationship until late October 2017, when, according to Packham, his daughter Nicola had confronted him about his extramarital relationships and said she would tell her mother, if he did not.
"At the time when his wife had found out about his extramarital relationships, there were discussions where he spoke of divorce as an option," she said.
Packham apparently told her he had spoken with an attorney over the phone about divorce options and later met with a family attorney.
A day before Gill went missing, she had coffee with him at the V&A Waterfront and "discussed whether he was coming to a decision with regards to his marriage".
On February 22, she received a message from Packham at around 08:30, wishing her a good morning and saying he had overslept.
Around 10:00, he sent a WhatsApp voice message saying he was feeling frazzled because his wife had not arrived at work and he was looking for her.
The ex-mistress said she suggested places he could look for his wife, thought maybe she had taken a day for herself, and also asked if his daughters or sister had heard from her.
Around two hours later, he called to say he had been driving around the routes his wife took and was going to see if she was at her favourite beach.
"The next time I heard from him was on my way home, just after 17:30. He said that they had reported her missing to the police. One of the suggestions I had made was to contact Pink Ladies because a colleague of mine had made use of them."
He apparently told her that Pink Ladies indicated they could only put an alert out once he had SMSed a case number.
The two met again on March 1 at her workplace, where they sat in his car. She conveyed her condolences and asked if there had been any leads in the case.
Packham said he was a person of interest because he was the last person to see his wife alive.
On March 25, she decided to end the relationship because his arrest had become very public and she felt it was not in her or her children's interests to remain with him.
"I did send a message from another phone, I said I felt I should step aside. He continued over a couple of months to try and be in contact with me, both directly and indirectly through mutual friends."
She got legal advice and sent a legal letter to Packham's counsel to ask him to stop all contact.
Prosecutor Susan Galloway asked if that had the desired effect.
"No it did not," she said, pausing and then sipping water. She said he made between 18 and 20 attempts to contact her, left items at her home and work, and tried to pass messages between mutual friends.
Galloway asked whether they had spoken about being a couple after Gill was found dead and she ended the relationship with Packham.
She replied that the only thing she could remember was an email she received on February 24, with a line that she recalled stating: "this madness will soon be over and we can be together".
Under cross-examination, defence lawyer Advocate Craig Webster said: "I put it to you that it was a time when he was very highly stressed and he has no recollection of sending that message".
She maintained that he had sent her the email at 02:00. She was then excused from the stand.
The trial resumes on Wednesday.