A pharmaceutical sales manager accused of stabbing his ex-lover to death has told a Sydney court he felt "hurt", "angry" and "stupid" when the young woman ended their relationship, telling her "you've ruined my life".
Paul Darren Mulvihill, 46, broke down while giving evidence in the NSW Supreme Court, where he is on trial for the murder of Rachelle Yeo, 31, in July 2012.
Mr Mulvihill has pleaded not guilty to the crime, claiming that he was acting in self-defence.
On Wednesday he recalled how, about two months before Ms Yeo's death, she ended their relationship, telling him that the anxiety caused by the fact that he was still married was too much for her to bear.
"She said 'Paul, I'm over the stress and anxiety of waiting for what Theresa [Mulvihill's wife] may do'," Mr Mulvihill recalled.
"She said: 'I've just started a new job [in Sydney]. I can't deal with the stress caused by our relationship ... Paul, I think it's time that we stop seeing each other, once and for all.'"
The 44-year-old former representative rugby player told the court that he tried to convince Ms Yeo not to end the relationship and that he felt "hurt", "angry", and "a bit stupid" when she insisted on doing so.
"I was heartbroken in a way," he said.
"I had had the opportunity to walk away from the relationship. I know I should have done that ... I felt a bit stupid because I had decided to pursue the relationship and now it was coming to an end."
Mr Mulvihill recalled meeting Ms Yeo on a number of occasions in the days that followed, including at the office of the company where they both worked, in an attempt to change her mind. But she refused to do so, telling him: "Paul, this is the best thing for both of us."
He admitted to throwing his laptop during one meeting in a hotel room after the 31-year-old refused to tell him the location of a new apartment she was moving to.
He said that on another occasion he threatened to send her love letters to their work colleagues.
"I was very angry, I said: 'Rachelle, you have ruined my life ... I will show everyone the love letters and emails you have sent me and show people who you really are ... You're so concerned about your reputation."
"I'm not sure I had any intention of doing that - I didn't do it, it was just a comment I made in the heat of the moment."
Later, Mr Mulvihill described how he found out where Ms Yeo lived by peering into her car and seeing an addressed envelope.
"I desperately wanted to talk to her and I thought that the only way that was going to happen was by going to see her," he said.
"The relationship ended so suddenly ... I felt I needed to get some things off my chest."
He then explained why, when he left his hotel on the night of the alleged murder to drive to Ms Yeo's home, he put the hood of his jumper over his head.
"I knew that I shouldn't be going there because the work implications were that I could have lost my job," he said, referring to a warning he had been given by his employer to stay away from Ms Yeo.
"If Rachelle made an issue at Sanofi the next day about me going there, I was just going to deny it."
"I just needed to have that conversation, to find out exactly what happened, where she was at."
The trial continues.