The two women lived together and had an intimate relationship in 2010.
Then, on May 26, 2011, one killed the other after they celebrated the victim's 36th birthday with friends.
Ms Celine Ng Swee Peng's skeletonised remains were discovered only 40 days later in Clementi Woods, where derivatives dealer Ang Soo Hoon had dumped her body.
Yesterday, the slim and boyish-looking Ang, now 40, was jailed for 12 years and six months after pleading guilty to one count each of culpable homicide not amounting to murder, dishonest misappropriation of property and giving false information to a public servant.
Two other charges - failing to report Ms Ng's death and moving her body without reasonable excuse - were taken into consideration during sentencing.
There were no witnesses to the crime and the bizarre circumstances leading to the homicide, the attempted cover-up and disposal of the body are based on Ang's confession to the police.
Deputy Public Prosecutor (DPP) David Khoo told the court that Ang, Ms Ng, a property agent, and three friends went to the Lantern Bar in the Fullerton Bay Hotel at around 10pm on May 25 to celebrate Ms Ng's birthday.
They then went back to Ms Ng's apartment at West Bay condominium on West Coast Crescent for more drinks. The friends left at 4am the next day.
Ang claimed that Ms Ng became upset when her calls to a former lesbian lover went unanswered.
She asked Ang if she was her best friend and if Ang would do anything for her. Ang said that she would.
DPP Khoo said that Ang claimed Ms Ng then asked her "to help her die", but she declined because "she did not know how to do so".
"(Ms Ng) took a red dumbbell and attempted to hit her own head with it, but the accused managed to grab (it) away," he added.
As they struggled, Ms Ng asked Ang to smother her with a pillow. Ang agreed, but was unsuccessful because Ms Ng pushed away the pillow.
When Ms Ng called her "useless", Ang became furious and wrapped her right arm around Ms Ng's neck to strangle her.
For someone who wanted to die, Ms Ng put up a big fight, kicking and grabbing Ang's right arm.
But Ang would not let go. Instead, she applied extra force and used her body weight to tighten her lock on Ms Ng's neck.
She released her grip only after she got tired. By then, Ms Ng was "unresponsive and had stopped breathing", said DPP Khoo.
THE COVER-UP PART 1
Later that day, Ang told Ms Ng's mother, Madam Chua Beng Lau, over the phone that her daughter had gone out before she woke up.
She decided to cover up the homicide. To make it appear that Ms Ng had gone on an overseas trip, she took her friend's passport, packed an overnight bag and threw it down a rubbish chute.