Sex counselor Mok Tai-hung (Eddie Cheung) and sex therapist Lam Ching-yee (Sharon Chan) have been dating for five years. The two love each other very much and want to take their relationship to the next step by getting married. But Ching-yee's strict and conservative mother Liu Doi-lam, is highly against them being together due to Tai-hung's financial status, him being a bit older than her daughter and also him having a son from a previous relationship. Tai-hung puts up with Ching-yee's mother bias of him and hopes she will come around one day. After the two are married they still find roadblocks in their relationship as Tai-hung constantly has to put up with his new mother in-law to show he is the perfect son in-law. While Ching-yee has to adjust to life at Tai-hung's family home and tries not to offend her mother in-law who overly tries to be helpful but only makes matters worst.
Tai-hung's immature friend Kam Cheung (Louis Yuen) once lived an affluent life, until he was swindled out of his inheritance. Now he lives a desolated life in a small rundown apartment where he can't even afford to pay his electric bill. When he cons Tai-hung's equally immature younger sister Mok Siu-tou (Elena Kong) into lending him money to start his underwear business, he didn't expect her to cling onto him until he repays her. Tai-hung helps Cheung repay his debt to Siu-tou, Cheung does not learn his lesson and uses Siu-tou's identity as a co-signer when he takes out a loan from loan sharks.
Meanwhile, Ching-yee's uncle Liu Chun-cheung (Benz Hui), who is in his late middle age is getting married for the first time. His much younger newly wed wife Tong Tim-tim (May Chan) just immigrated to Hong Kong from mainland China, not long after marrying Chun-cheung. Ching-yee's mother Liu Doi-lam. who has taken care of her dependent older brother all her life does not trust Tim-tim and is afraid that Tim-tim will con her brother, even when the entire family tells her, Chun-cheung doesn't have anything worth conning. The problem with Chun-cheung and Tim-tim's marriage is, he finds himself unable to keep up with his wife's sex drive as she wants to have intimacy every night. Even with the help of his friends in helping him avoid having sex with his wife each night, Chun-cheung finds himself unable to resist Tim-tim when she is in costume for foreplay.
At Ching-yee's younger sister's high school, extreme conservative literature teacher To Tak-kee (Sammy Sum), feels that all the students should be like him, remain a virgin until marriage. When he sees students from his ultra conservative all girls school mingle with the opposite sex from another school he goes as far as to stalk them after school and then telling them to stop seeing the male students from the other school or else he will tell their parents. When Tak-kee finds out that fellow teacher Emma Chung (Grace Wong) lives a promiscuous life outside of work he threatens to tell the school principle. Emma won't allow him the chance to tell the principle about her secret lifestyle, when she tries to seduce him and then uses that against him.