They had a reason for being unhappy. They were tricked by their mother who brought them to the Tanglin Quit-Smoking clinic.
Mum, Mariam Samad, took medical leave to bring her sons to the clinic. She was desperate.
She was at her wits end trying to get her sons, Amirul, 16 and Amir, 14 to quit smoking, a habit they had developed three years ago.
She tried nagging, scolding and giving them health scares. Nothing worked.
The mother moved them out of their boarding school after she learnt that they had picked up the habit there.
"They stank of cigarette smoke when they returned home for holidays."
The 42-year-old woman transfered her sons to a day school, hoping she and her husband could pay more attention to their sons' activities.
But that too was in vain. The boys were still at it.
Running out of options and hearing about the clinic, Mariam, brought her sons there last month.
"I am just so afraid they will soon start taking drugs," said Mariam, adding that Amir needed to stop smoking immediately as he was asthmatic.
She had tried talking to them but without much success.
"You know teenagers. It is very hard to talk to them," she said.
Before hearing about the Quit-Smoking clinic, Mariam tried to buy nicotine replacement drugs but found them to be expensive at RM150 for a three-week supply.
At the counselling session, the brothers were told that the cigarette is like a devil, which destroys the body and mind.
Amirul felt motivated to quit especially after reading the pledge to quit smoking for good. He could see the light at the end of the tunnel. "I am going to try to quit because I want to be healthy," said Amirul after the session.
He said he did not like to see his lips turning black. He also had a girlfriend to think about.
Amirul, in recalling his smoking activities said he would smoke when he went out to town with his boarding school friends.
"I began to smoke because I was bored. School was not a challenge to me," he said.
Now he said he would make an effort to quit smoking by not thinking about smoking.
Instead he would concentrate on his new hobby -- dancing.
Over the past six months, Amirul joined his friends in taking part in the shuffle dance.
He felt sorry that his younger brother had also picked up the habit but said he did not teach him.