Teenagers - and their teachers - are largely unaware that deep kissing is a crime before age 16, research has revealed.
Exposing a hole in adolescents' knowledge, a church study found students did not realise that fondling and passionate kissing can be classed as indecent assault.
"Indecent assault can include deep kissing, such as with love bites, and fondling … and unlawful sexual intercourse includes oral sex as well as vaginal intercourse," said criminologist Keswick Chuk Wing-hung, a director of the Youth Enhancement Scheme at the Evangelical Lutheran Church of Hong Kong.
"It doesn't matter if the acts are consensual. If teachers or parents suspect teenagers of engaging in such activities, they should report to the police."
The church studied 88 cases of youths cautioned by police for sexual offences.
Boys rather than girls are usually charged, often receiving an official police caution, which will not show up as a criminal record.