In the fading daylight they come out by their dozens -- young men in small groups or alone, cruising Phnom Penh's parks for sex, not with female prostitutes but with each other.
"Having sex with men is just something I like to do, it's relaxing," says a pub manager who gave his name as Pov as he sat among drinkers, all men, at his bar a few blocks off of the capital's busy riverfront.
In Cambodia, as elsewhere in the region, men having sex with men is nothing new.
But Pov's world, like that of many Cambodian men who are known as "MSM," is defined by secrecy and, in some cases, self-delusion and denial.
MSM -- men who have sex with men but who may not consider themselves to be homosexual or bisexual -- account for four percent of Cambodian men, according to experts, and represent a ticking HIV/AIDS timebomb.
Pov admits that his wife in rural Cambodia, whom he sees a couple of times a week, has no idea about his trysts with two or more male partners a month.
But he says he does not consider himself to be homosexual, or even bisexual, despite his predilection for sex with men.
Health workers say this growing and largely unseen trend towards risky sex threatens to seriously undermine progress in tackling one of Asia's worst HIV/AIDS epidemics.
Aggressive condom and sex education campaigns largely targetting Cambodia's sex industry effectively halted a spiralling HIV infection rate that in 1997 peaked at 3.7 percent of the country's approsimately 11.5 million people, making Cambodia the Asia-Pacific region's worst-affected country.