"He knew the consequences of telling his imam – just as Jewish kids know that most synagogues will stigmatize them rather than help. He had nowhere else to go," says the rabbi in a characteristic punchy burst.
"The similarities between our peoples are striking. Some parts of both our communities are very insular and will not face up to the trials of the modern world. But drugs don't care for religious distinctions: If you are Jewish or Muslim and have a drug problem, you are likely to face [ostracism] from your family and community. It cannot be right to abandon people when they most need help."
To those who know him, Sufrin's response to the young Muslim was entirely predictable: He opened the door and offered the same crisis intervention, advice, and counseling he has offered to Jews since 1990.
What came next was less expected.
Procuring a £115,000 ($190,000) grant from the local government council, and with the support of a progressive local Muslim imam, Haroon Patel, the diminutive rabbi launched a ground-breaking interfaith drugs project.
Dubbed "Joining the Loop," it provides advice in Bengali, Urdu, and Gujarati – three languages spoken by Southeast Asian Muslims – and crisis support to Muslim addicts and their concerned families with nowhere left to turn.
Several local mosques agreed to promote Drugsline's services – a step that itself was remarkable, given the enmity and mutual suspicion between the two faiths.
But taboo-busting is nothing new to Sufrin. His more than 18 years of drug rehabilitation work has been showered with criticism from sections of the Jewish community – which even bestowed him with the not entirely playful moniker of the "Drugs Rabbi."
But Sufrin remains sanguine in the face of his doubters. "Nobody from a 'good Jewish family' talked about drug addiction," he explains. "It happened to someone else's kids.
"That picture has changed quickly, and more and more teenagers are at risk of falling into drug use, even from the ultra-Orthodox families – whether they choose to see it or not. I hope we are softening attitudes with our work."