Social workers have warned against using long, confusing words when teaching children about sex education. A cartoon shown at a preview session of the Family Planning Association's sex education open day was criticised as too vague for describing sexual abuse as the 'touching of private parts'. 'If I were a kid, I might not know where I shouldn't be touched,' said Chiu Kam-hing, a social worker from the Hong Kong Federation of Youth Groups. A mother, Lau Siu-fong, said it was not that difficult to teach kids where the 'sensitive parts' were. The cartoon was among new sex education kits prepared or bought by the association at its first open day for their Sexuality Education Reference Library. Display boards, games counters, teaching kits and publications were also shown, but visitors seemed more interested in the prizes. Ho Chiu-kin, 10, having watched the video and visited all the games counters, said the games were great fun. He said he had learnt that he should protect himself from sexual harassment - although he could not remember how.