Lan is shocked to learn that Kiu has not had sex with Yam for six months and she believes that Yam must have been seeing someone else. She is determined to find proof with the help of their youngest sister, Wai. Hei defends Yam as he once followed him and knows that he is really busy with work. However, shortly afterward, Hei discovers that Yam frequently hangs out in nightclubs and then Hei regrets that he defended him. Hei uses an AIDS prevention promotion leaflet to remind Yam to behave. But Yam thinks Hei is infected with the deadly disease. After clarification, Hei discovers that Yam is suffering from a pain that any man would keep to himself… Kiu is finally done with her language aptitude test. With the help of Lan and Wai, she plans for a romantic night with Yam. Hei, in order to save his father, proposes an idea…