刘苹果（范冰冰饰）在北京一家洗脚城里做按摩妹，丈夫安坤（佟大为饰）是负责清洗高楼落地窗的工人，二人生活贫困，却相亲相爱。 　　洗脚城老板林东（梁家辉饰）是个好色的港商，时常找不同小姐满足生理需要。老婆王梅（金燕玲饰）不能生育，经营一家美容院，两人感情冷淡。 　　一日刘苹果的好友小妹因为得罪客人而被开除，二人喝得酩酊大醉。神志混乱的苹果误打误撞走到一间足浴客房，正好是林东的休息室，二人发生关系，却被正在刷窗的安坤看到。 　　安坤欲借此敲诈林东，并前去找王梅谈判，愤怒的王梅要林东也尝尝“戴绿帽”的滋味，于是与安坤发生关系。 　　而在这时，一个更大的变故产生。苹果怀孕了，而到底谁才是这个孩子的父亲成了林东与安坤赌博的筹码，四人签订协议，如果是林东的骨肉，他将给二人十二万元的补偿费，而如果是安坤的，则双方互不相欠......Lin Dong and Wang Mei are a childless couple in Beijing, wealthy, approaching middle age. Lin owns a foot-massage parlor. One afternoon he rapes one of his workers, Liu Pingguo, who has nearly passed out from drinking alcohol with a friend. Part of the assault is witnessed by Liu's husband, An Kun, a window washer. He's angry with the boss and with his wife, and he seeks compensation. Lin's wife counsels him and joins in revenge. Then, Liu realizes she's pregnant and a set of emotional calculations ensues: Lin wants to buy the child, Wang agrees but has conditions, An Kun goes back and forth and barely contains his anger; Liu withdraws. The baby comes. Can anything be sorted out?