You are a happily married woman out for dinner with your husband. He leaves his phone on the table while he goes to choose the wine, and a message flashes up on the screen. Ping. Thats all it takes for your life to unravel as you discover that not only is he on dating app Tinder, but hes been having sex with a string of women. Some of them live in the same block as you. This isnt a salacious Desperate Housewives plot. Its a real-life scenario that has played out in Hong Kong. Sex addiction wrecks families, destroys relationships and burns careers. And it is behaviour that counsellors are seeing more of, thanks to the increased use of dating apps. These people are your neighbours, they are parents at your kids school, they are people sitting around a dinner table. The knock-on effect on normal living is massive, says Fiona Markham, chief clinical officer at The Cabin, an addiction treatment and rehabilitation centre based in Chiang Mai, Thailand. Primary sex and love addiction clients account for one in four cases at The Cabin, which has an outpatient addiction counselling clinic in Hong Kongs Central district. That marks a 30 per cent increase on the previous year.