Kathmandu, May 7 -- It began with what seemed like a harmless offer, a small pill that promised to help Sagar, a nervous 21-year-old on a date in Thamel, relax and enjoy himself. The man he had met at a bar was older and persuasive. "He said it would make sex better," Sagar recalled, describing his first experience of chemsex (a slang term for sex under the influence of drugs) two years ago.

For Sagar (whom the Post is identifying with a pseudonym for his privacy), that night, everything felt heightened but blurry. He is not sure if they used a condom. He is not even sure he could have asked. "It felt thrilling at the time," he says. "I didn't realise the kind of danger I was exposing myself to back then."

Sagar's experience is not uniq...