For two years, she watched helplessly as her husband repeatedly kicked, slapped and pinched her son.
When she tried to intervene, she ended up being assaulted and suffered a gash above her lip on one occasion.
"I felt that I was not fit to be a mother. I felt so guilty because there was nothing I could do to save my son from my husband's beatings," said the housewife in her late 20s, who wanted to be known only as Madam Fifi.
On Tuesday, her seven-year-old son was admitted to hospital after his teacher noticed injuries on his head and thighs, after the latest thrashing by his stepfather.
Said Madam Fifi: "I was not surprised because his injuries were quite bad. I am thankful because all these years, I did not dare to seek treatment for him as I was afraid of what my husband would do to me."
The husband, a 27-year-old cleaner, has been arrested for child abuse, a police spokesman said.
Madam Fifi told The New Paper yesterday that she had married her husband in June 2012.
It was her second marriage.
"Back then, he was a sweet talker and was very loving. Things changed after I gave birth to my second son two years ago.
"He became hot-tempered and violent and he started beating my older son, who is from my first marriage," she said.
For about two years, he would beat her and her first son whenever things do not go right for him at home.
"At first, I tried to stop him, but he ended up hitting me as well. Once I had a gash above my lip that required two to three stitches.
"After that, I became fearful. I wanted to help my son, but many times I would end up trembling and not be able to move," Madam Fifi said.
BEATINGS CONTINUED
She said she applied for a personal protection order against her husband last year, but the beatings continued.
The latest incident happened last Saturday when she was preparing food in the kitchen of their one-room rental flat in the west.
"My two boys were playing, running around and making a lot of noise. I told them to be quiet as my husband was sleeping after his night shift,"
Madam Fifi said.
But they ignored her and woke up their father.
"He took it out on my older son by kicking him in the chest and picking him up and throwing him onto the floor twice."
The boy suffered bruises on his thighs and a cut on his right ear. His teacher saw the injuries on Tuesday, she said.
"I didn't even know that he was admitted to hospital until a social worker told me. But I'm glad he could receive treatment," said Madam Fifi, who then made a police report.
Her son has been discharged and is recovering well.
Madam Fifi and her two sons are under police protection for the time being.
"The child protection officer told me that it's risky for my boys to go to school for the time being as it's near our home. But I'm afraid they may miss out on lessons and homework," she said.
A police spokesman said a 27-year-old man was arrested for breaching the personal protection order.
He is assisting in investigations.
Madam Fifi said she had suffered for almost three years in the hope that her second marriage would work out.
She said: "I didn't want to break our family apart. But now I hope for justice to be done.
"I realised I should have told my neighbours so they could look out for my children and me. This has been a painful but important lesson."