剧情介绍
刚刚成年的Yoyo（蔡卓妍饰）有众多的追求者，所以总是充满自信，觉得自己魅力非凡。她应父母的要求到英国跟指腹为婚的张十三（郑伊健饰）完婚。两人对这种荒谬的事情深感厌烦，却又无法违背长辈的意思，于是两人假扮结婚，一年后自动离婚。
张十三把外婆的家传宝带到香港给Yoyo，Yoyo为了留下十三收取房租，便告诉十三到自己就读的女校任教，可以有助他为自己的硕士命题收集材料。
十三帮Yoyo结识男孩子，Yoyo失恋，十三帮她治疗情伤，最终两人也发生了关系。相处多时后，两人恋上了彼此，但Yoyo的体育老师（廖碧仪饰）也爱上了十三，到底十三要如何选择呢？ After finishing the open examination for Form 5 students and applying for an adult identity card, Yoyo, eighteen, departs for London to meet a guy introduced by her well-meaning parents in Britain. The guy, named Cheung, is in his thirties. Yoyo's and Cheung's grandfathers were wartime buddies. They swore to have their unborn babies get married when they grew up. However, the babies turned out to be both women. The two women are now mothers. They come across each other again and want to make their fathers' wish come true, so they arrange for Yoyo and Cheung to meet in London. Yoyo and Cheung promise to get marry in order to please their mothers. But on the wedding day, they also sign a divorce agreement which is effective one year after their marriage. The pair wave farewell in the airport and Yoyo returns to Hong Kong to further her studies, while Cheung continues to write his unfinished dissertation. But they will meet again ...
张十三把外婆的家传宝带到香港给Yoyo，Yoyo为了留下十三收取房租，便告诉十三到自己就读的女校任教，可以有助他为自己的硕士命题收集材料。
十三帮Yoyo结识男孩子，Yoyo失恋，十三帮她治疗情伤，最终两人也发生了关系。相处多时后，两人恋上了彼此，但Yoyo的体育老师（廖碧仪饰）也爱上了十三，到底十三要如何选择呢？ After finishing the open examination for Form 5 students and applying for an adult identity card, Yoyo, eighteen, departs for London to meet a guy introduced by her well-meaning parents in Britain. The guy, named Cheung, is in his thirties. Yoyo's and Cheung's grandfathers were wartime buddies. They swore to have their unborn babies get married when they grew up. However, the babies turned out to be both women. The two women are now mothers. They come across each other again and want to make their fathers' wish come true, so they arrange for Yoyo and Cheung to meet in London. Yoyo and Cheung promise to get marry in order to please their mothers. But on the wedding day, they also sign a divorce agreement which is effective one year after their marriage. The pair wave farewell in the airport and Yoyo returns to Hong Kong to further her studies, while Cheung continues to write his unfinished dissertation. But they will meet again ...
《我老婆未成年》十年前，2002，她18他30，早熟和晚熟因互相吸引而在一起，她傻傻的以为漂亮就不会失恋，于是在耍了无数男孩后，被喜欢的男孩拒绝，在最伤心最虚弱时因他细心的照顾而痊愈，于是她孩子气的要做英雄放走爱的人，又孩子气的舍不得把他追了回来，一场假结婚成就了真爱情。
睡前等頭發乾，這種電影最好了~當年鄭伊健還很嫩（¯﹃¯）…這電影論證了陸琪一句話【女人如果遇到好男人，一辈子都不需要成熟起来。】太獨立的女人都不會撒嬌賣萌耍賴的，女人都沒這點風情了，多沒意思呀~到時男人變兒子，女方化身聖母黃臉婆，嘖嘖~有些得提前說好了，譬如…人家就喜歡折騰喜歡
重温天真无邪俏皮sa，感叹郑伊健那时候真是风度翩翩帅气逼人，还学到了好多整欧巴的招数哦～～欧巴，Are you ready？？
为了保留阿sa青春单纯的yoyo形象我打算不看第二部了！伊面还是好帅好帅，而且作为叔控绝对不能接受第二部叔唔生性的设定啊！and伊面要和现实的yoyo结婚了，皆大欢喜大结局！
睇过几次了，都系觉得好搞笑。当时噶阿sa真系好鬼嫩，yoyoma。
和高中生谈恋爱好累人啊，但也超有活力
两个小时对我来说有点漫长~因为只有几个片段觉得有趣~其他部分粤语听着灰常不舒服。被捧得跟天仙似的阿sa好像谢娜，叽叽喳喳让人烦，郑伊健在里面穿着土气，但颜很正。十年之后一批人又拍了个翻版，只可惜岁月是把杀猪刀，让我没有期待。现在力宏都在时间的摧残下谢了容颜，其他人更是老的快~讨厌呜呜~
听说要出续集了..才想起这个片子..情节轻松卡司喜欢..不知道隔了10年还能有旧作几分神韵..希望别弄的跟河东狮吼似的就好..
这部电影是我初二的时候看的，那时候的twins还是恋爱大过天的青春少女。特别喜欢阿Sa在这里面的演出，无敌阳光美少女，为爱情不顾一切。
嫩媳婦帶來的各種傻事與貼心。
英雄末路，可美人正在长成。最爱曾经的陈浩南，也最希望现在的郑伊健能有最简单纯粹的幸福。
阿Sa在我心中最经典的角色永远是这个yoyo。纯洁、天真、可爱、阳光、快乐、勇敢，又有些小聪明，叫我们怎能不爱她？
阿sa真的很可爱~不知道在拍这部戏的时候阿sa和郑中基有没有来电-o-
这种片我居然也看过——在放假的时候电视上看的。 没啥感想，只是我已经对郑伊健演帅哥永久性的审美疲劳了。
2002.12.28-29/2009.10.10