SINGAPORE - His lover was carrying their child and wanted to get hitched but she did not know he was married with children, and would not be able to register their union.
To get around this, Ong Tiong San paid someone $120 to stage a solemnisation ceremony at his home and created a fake marriage certificate by modifying a scanned copy of his real one.
He repeated the trick after she gave birth in February, this time using his son's birth certificate as the template for a bogus one.
Ms Zhao Dan, a Chinese national, remained none the wiser. But the deception finally fell apart when the retail supervisor returned to work in May, and submitted the false documents to claim maternity leave benefits from her employer.
On Wednesday, Ong, 43, was fined $10,000 after pleading guilty to two counts of forgery.
It is understood the couple met while working at NTUC Fairprice where he was then a division manager.
The court heard that on Jan 25, Ong used computer software to produce the phony marriage certificate. This stated that his purported union with Ms Zhao, 30, had been solemnised by an assistant registrar of marriages.
Sometime between late February and early March, he made the fake birth certificate, which said their newborn girl was a Singapore citizen.
He later paid NTUC Fairprice $4,067.30, for the 48 days of maternity leave Ms Zhao was not eligible for.
Calling for the $10,000 fine, Deputy Public Prosecutor Eunice Lim said the documents forged were of a serious nature.
District Judge Carrie Chan called Ong's offences "shocking", noting his previous convictions in 1992 and 1999 - for criminal breach of trust and cheating - both involved dishonesty. She noted Ong had planned the forgeries and deceived his lover for a long time.
The judge noted that forgery carries a maximum jail term of four years, and warned Ong imprisonment was likely if he were to reoffend.
Ong has two children from his existing marriage, for which divorce proceedings are expected to conclude in two months.
He also admitted making a false statement at the Immigration and Checkpoints Authority that the couple were married when applying in March for the child to be given Singapore citizenship.