吳德威與張小妹同居剛滿七年. 小妹持家有道, 唯她醉心於粵劇, 常惹丈夫討厭, 而吳個性內向, 七年來從不敢拈花惹草, 但漸感生活枯燥無味. 一次, 吳赴星加坡公幹, 機場內, 遇一扒手小紅, 因被警方追蹤, 手上一批珠寶無處脫手之際, 她遂將珠寶巧計放入吳之行李內. 飛機上, 小紅為奪回珠寶, 乃向吳大施美人計, 趁機取回珠寶, 臨行前留下絕情書一封. 吳以為小紅不忍破壞其婚姻幸福, 竟大為感動, 對小紅念念不忘. 吳提議與妻到星加坡渡假, 實則只為回味一段霧水情緣, 誰料旅途上一中年富翁錢多多垂青於小妹. 另一方面, 小紅發現尚有一寶介留於吳之行李上, 於是再次找吳, 不料陰差陽錯, 小妹誤會其夫另結新歡, 遂答允錢多多婚事. 後吳知悉小紅存心利用, 但賢妻即隨他人遠去, 吳唯有想辦法為其幸福婚姻展開救亡……

An introverted businessman who doesn't get out much, Willie Ng recently celebrated his seventh anniversary, but his marriage seems to be hitting a slump. His wife is a Cantonese opera aficionado who often complains that her husband is boring and doesn't appreciate the arts. Willie himself is also eager for some action to break the monotony. When he goes to Singapore on a business trip, he encounters cute pickpocket Siu Hung at the airport, triggering off a series of events that puts his marriage in jeopardy.