His eyes were wild.
He was blowing into a plastic bag full of slightly yellow glue and then inhaling from it. He stopped every one or two minutes to spit.
The scene is common among groups of teenagers at Ho Chi Minh City parks these days.
The habit of sniffing glue for a cheap high first became popular among city teenagers around two years ago and the trend has shown no signs of abating.
"They do that every day," said a city resident playing tennis at the Cultural House of District 10 on Monday last week. "They gather here in the afternoon. So weird, I don't know what they have in mind, sniffing a thing so strong and so toxic like that."
Glue-sniffing groups of both boys and girls often gather in far larger numbers than they used to. Some "groups" have more than 100 "members" sniffers.
One sniffer in District 10, only identified as K., said it was easy and cheap to start the habit as one only needs a plastic bag and some iron or wood glue.
"The glue is sold at stores all around. Just spend VND20,000 and you can sniff the whole day. Try, you won't die, don't worry," K. said.
Asked about warning label on the glue boxes saying the glue must not be inhaled, K. said he didn't care. "Just sniff and you'll know, it fells extremely good."
Another new sniffer named T. said he tried recently and really felt "happy".
"I joined the group late, so I have to buy the glue myself. Older brothers don't have to buy as new members will give them the glue for free to be taught how to sniff," T. said.
The glue that sells at store for VND3,000-20,000 a tube creates a feeling of euphoria and is now one of the city's most popular recreational drugs.
"I can stop eating for a day, but I cannot stand it without sniffing glue," T. said.
Le Quoc Nam, a mental health doctor, said glue sniffers usually turn to the substance after suffering stress or frustration.
The glue brings an excitement that always entices more use, Nam said.
It is an addictive drug and the sniffers develop a tolerance to continually use bigger amounts, he said.
Nam said the industrial chemical will cause afflictions in the central neural system, depression and damage to lungs, liver, kidneys, bones and heart.
Test results in 2008 showed that certain glue sniffed by teenagers contained at least three toxic substances methylene choloride, ethyl acetate and toluene.
Psychologist Huynh Van Son said the way old sniffers teach new ones, and new ones help old ones, will draw more teenagers to the habit, and other crimes.
Son said parents should watch their children more closely to notice any change in their mindset or behavior.