锦恒（吴镇宇 饰）和Henry（陈锦鸿 饰）是一对好同事兼好友，同在一家杂志社担任负责人。虽然两人是好友，但两人的性格却相差甚远。锦恒为人老实，甚至有些古板，而Henry则大方开朗、生性风流。两人都已经成了家，锦恒和妻子Ivy（李婉华 饰）婚后一直过着平淡的生活，虽然感情稳定，却毫无生气；而Henry的妻子Linda（彭杏英 饰）和他性格相当，两人虽然经常打打闹闹，但比起锦恒他们却也热闹许多。

Ma publishes books; his marriage is flat and his wife wants attention, so she arranges a photo session in bed with Si, a gay decorator, to make Ma jealous. Her friend, Linda Lo, also unhappily married, is there as well, dressed for the photos, and Si's lover is hiding in another room. Enter Henry Lo with a call girl, and Ma himself, intent on killing Si. Chance intervenes: a best-selling author and a prude, Lovely Pak, pays a call; she wants Ma to publish her books. Mistaken identities and everyone's attempt to seem conservative to please Pak lead to chaos: Si pretends to be Ma; Ma pretends to be a servant. Will Miss Pak sign a contract, and can the married couples find harmony?