Perhaps it is a case of "like father, like son".

Bryan (not his real name), 10, came home one day and saw his father watching a video through a partly open door. Curious, the Primary 4 boy inched forward and saw naked people on the screen.

Puzzled, he went back to his room and tried to search for it on his own smartphone. It did not take long before he discovered pornography and became hooked. Every night before he slept, he would watch it secretly for half an hour.

By Primary 6, he was sharing video links and images with other boys in school. They would often gather in groups to view or discuss what they saw.

Bryan got bolder in secondary school. He engaged in cyber sex on online forums and chatrooms to experience "another level" of sexual fantasy and experience.

He also downloaded many nude photos of women from porn websites on his smartphone.

While he was watching sex scenes one day, he was caught by his mother, who came home unexpectedly. His parents flew into a rage and confronted him. Embarrassed, Bryan ran away from home.

The next day, his parents and friends found him loitering around the neighbourhood and persuaded him to return home.

"But his parents were at a loss as to how to help their son," said manager Chong Ee Jay of Touch Cyber Wellness, an agency that conducts online safety talks. "They didn't want to open up to the school counsellor as they feared how the school would view their son."

Mr Delane Lim, chief executive of youth development company Agape Group Holdings, said he encountered a similar case in an elite secondary school earlier this year.

He was conducting a youth leadership camp when he noticed a group of Secondary 2 and 3 boys giggling during discussion time. He found out they were watching a Japanese porn movie and spoke to them.

"The leader of the group said he knew about the site after he chanced upon it on his father's iPad," said Mr Lim.

When probed further, the teen argued that pornography was art and a form of sex education that would prepare him for manhood.

His father was called in, but challenged the teacher: "What's wrong with it? He is growing up."

Said Mr Lim: "The boy was sent for one or two sessions of counselling, but the fact that he knew his father was watching porn would have made it harder to convince him of the danger of cultivating such a habit or addiction."

In Bryan's case, he was counselled and had monitoring software installed on his phone for the next three months. He is also being mentored by a support group.

"It is an up-and-down journey of recovery for him, but he is less addicted now," said Mr Chong. "More importantly, there is a trusted community he can turn to for help."