It started casually with her colleague offering to take her home after work.
As the rides became regular, Madam Serene Goh grew close to Mr Dexmon Chua and they confided in each other about their marital problems.
Despite being married, they took their intimacy to another level and started having sex.
Their trysts carried on for about a year.
Her husband, Chia Kee Chen, later found out about the affair.
A year later, Mr Dexmon was found dead with severe head injuries.
Chia is now on trial for murdering Mr Dexmon, 37, who worked as a materials analyst at food packaging and processing company Tetra Pak.
Chia is accused of - with the help of Indonesian Febri Irwansyah Djatmiko - forcing Mr Dexmon into a van and assaulting him until he died.
Another accomplice, Chua Leong Aik, drove them to Lim Chu Kang, near the area where Mr Dexmon's badly decomposed body was found.
Yesterday, Chia, 56, pleaded not guilty and said: "I did not do it. I did not murder him."
His 51-year-old wife, the mother of their two girls, took the stand for about 10 minutes. Her statement to the police was read out to the court.
The court heard that Madam Goh was a sales executive at Tetra Pak from 1995 till September 2013, when she was retrenched.
She had known Mr Dexmon since 2003 as they took the company transportation to and from work from their Choa Chu Kang homes.
In July 2011, he contacted her on the company's instant messaging system and offered her a lift home after work.
She turned him down but accepted when he offered a second time.
From then on, they grew closer and she would regularly hitch a ride home from him.
They also started texting, calling and communicating via the office instant messaging system.
It was also around then that Madam Goh received an overseas call from a woman who claimed she was Chia's wife in Indonesia, where he owns a fish farm.
Madam Goh told the authorities this was not the first time she had received such a call.
When she confronted her husband, he denied having an Indonesian wife.
While she claimed she trusted Chia, she began confiding in Mr Dexmon, knowing he was married to a Thai woman.
He did the same, sharing his marital problems with her.
In August 2011, Mr Dexmon suggested to Madam Goh that they become intimate, and she agreed.
They would meet after work and have sex in his car, at his home, and once at a hotel.
Madam Goh said in her statement that she felt "guilty" during the affair with Mr Dexmon.
But they both could not bring themselves to stop the affair.
In June 2012, with her permission, he recorded themselves having sex, twice, for "sentimental purposes".
They stopped having sex soon after and began quarrelling often, but still communicated over the phone.
Later that year, Chia found Mr Dexmon's text messages on his wife's phone and confronted her when their two daughters were asleep. She admitted to the affair.
She also said there were videos and pictures of her having sex with Mr Dexmon, which she feared he would spread.
Enraged, Chia called Mr Dexmon using her mobile phone and scolded him in Hokkien, telling him to end the relationship.
Mr Dexmon allegedly told Chia that he had deleted the racy videos and photographs.
Madam Goh said she stopped her relationship with Mr Dexmon after that.
In early 2013, Mr Dexmon mistakenly sent Madam Goh a Chinese New Year greeting through Whatsapp.
Chia found out and became agitated, but Madam Goh assured him their affair was over. That was the last time they spoke about Mr Dexmon.
After his wife's testimony as a prosecution witness, it was the defence's turn to cross-examine her.
But Chia told his lawyer Peter Fernando not to do so.
In the early hours of Dec 29, 2013, Madam Goh was awakened by a call from her husband, who asked for the phone number of her brother Goh Beng Guat.
Prosecutors said Chia went on to ask Mr Goh for help to carry Mr Chua's body, but he said no.
That afternoon, Chia, Madam Goh and their two daughters left for a family trip to Johor Baru.
On Dec 31, 2013, they returned and were stopped by the authorities at Woodlands Checkpoint.
Chia was arrested that day and later charged with murder.
The trial continues today.
About the case
Chia Kee Chen is accused of killing Mr Dexmon Chua between 9.44pm on Dec 28, 2013, and 3.17pm on Dec 29, 2013.
Deputy Public Prosecutor Eugene Lee said in the prosecution's opening statement that Chia allegedly enlisted the help of Indonesian Febri Irwansyah Djatmiko, 33, who operated Chia's fish farm in Malaysia, to carry out the murder.
In return, Chia allegedly promised to set up a fish farm for him in Indonesia.
He also roped in a third man, Chua Leong Aik, 66, a cleaning supervisor.
On Dec 28, 2013, at about 10pm to 11pm, the three men lay in wait for Mr Dexmon at the multi-storey carpark near his Choa Chu Kang Avenue 4 home, said DPP Lee.
Febri and Chia approached Mr Dexmon after he had parked and alighted from his car, and allegedly assaulted him.
They were said to have forced Mr Dexmon into a van that Chia had borrowed, before tying up his arms and feet. Mr Dexmon was then allegedly assaulted some more by Chia and Febri until he died.
Chua was instructed by Chia to drive to Lim Chu Kang and told the authorities he heard banging sounds from the back of the van and smelled blood en route.
He later stopped and got out of the van as he was frightened and Chia allegedly took over the wheel.
Chia allegedly drove to the military live firing area in Lim Chu Kang and disposed of Mr Dexmon's body.
They went to a Lim Chu Kang fish farm where they spent an hour washing the van.
Chia and his family, joined by Febri, then took a trip to Malaysia.
Febri, who is still at large, is said to have returned to Indonesia by ferry from Malaysia.
Chia was arrested as he returned to Singapore.
In January, Chua was jailed for five years for abduction and voluntarily causing grievous hurt to Mr Dexmon.
Yesterday, DPP Lee said Mr Dexmon suffered extensive injuries to his face and head.
The prosecution will call over 80 witnesses during the two-week trial to prove beyond reasonable doubt that Chia murdered Mr Dexmon.
If convicted, Chia faces the death penalty or life imprisonment.
This article was first published on October 26, 2016.
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