Loneliness, curiosity, family breakdown and financial pressures are key motivators for young women to try it out, according to support workers on the ground.
High-school student Kiki, a pseudonym she chose to protect her identity, started part-time sex work aged 17, saying it was easy to search for men on Instagram by using one of the #ptgf tags.
She now has a full-time office job, but still does after-hours sex work to pay off her college debts as her family cannot afford to help.
After less than a year, she gave up because she had started a new relationship.Instagram said it acts to swiftly remove content, accounts and hashtags that violate its community guidelines.A long-term strategy addressing taboos around talking about sex within schools and families in Hong Kong's conservative society is what is most needed to stop girls putting themselves at risk, said Ms Lam."It's like you have a needle piercing your heart and it's always there." Connecting with clients online often gives young women a false sense of security, said Ms Bowie Lam, executive director of Teen's Key, a charity that offers support to Hong Kong's sex workers under the age of 25.She said the age of "part-time girlfriends" is getting lower and believed that social media is a factor.