今天要讲的三个习惯用语正巧分别有one, two, three这三个数词，而且都和浪漫情调有点关联。它们时常被用来描述男女间的恋爱关系。

1. one and only 爱人，情人，心上人
不论男女都可以用one and only来指自己的意中人，也就是你正式选定的情人。这一习惯用语沿用至今有一百来年了。
举个例子。说话的人要告诉我们他兄弟Bill的婚事，Bill马上要跟自己钟情多年的女朋友Mary结婚了。
例句-1：It's about time. Bill and Mary have gone together all through high school and college. For several years they've been each other's one and only. He never looked at another girl and she never went out with another guy.
现在差不多是时候了。Bill和Mary整个高中和大学年代都相爱。好几年来他俩一直是彼此的唯一情人。Bill从来没注意过别的女孩，而Mary也从不跟其他男孩出去约会。

2. two-timer 爱情不专一的人；骗子
Timer原来可以指按时计算报酬的工作人员，但是用在儿女私情上就不是那个意思了。Two-timer跟有忠诚不二的含义的one and only可说是恰恰相反。Two-timer指的是那种脚踩两只船的人。这种人三心二意同时交两个异性朋友，而且把两边都蒙在鼓里，骗得那两个人都相信自己是他/她的one and only。
例句-2：My friend Pete is a lonely man these days. He'd been going with Sally for a long time, and she thought he was serious about her. Then he started going with Pauline too, and both found out. There was a big fuss, and neither one wants to see the two-timer again.
我朋友Pete最近成了孤家寡人。他原来跟Sally谈恋爱已经很久了，Sally也认为Pete跟自己是认真的。后来Pete又开始和Pauline密切交往，结果Sally和Pauline都发现了实情，于是吵翻了天，两人都再也不想见Pete这心猿意马的人了。

3. three bricks short of a load 脑子缺根弦
Brick是砖头，大家一定知道short of这个短语的意思是缺少什么，而load是负载量，可能是一车或者一驮，也可以是一担、一船等等。
如今你不仅在校园里，还会在办公地点听到人们用three bricks short of a load来谈论男女恋爱关系。这一习惯用语的意思就是脑子里少了根弦，智力不够发达。
举个例子。说话的人要告诉我们的是为什么他妹妹Jennie对Elmer这小伙子无动于衷：
例句-3：Elmer isn't bad-looking; he's polite, well-dressed - a nice guy. But Jenny says his trouble is that he's three bricks short of a load; he's not smart at all and barely passes his schoolwork, so she just isn't interested in going out with him.
他说：Elmer长相不俗，而且彬彬有礼，穿着又得体，是个好人。但是Jenny说问题在于他一点都不聪明，学校功课刚勉强及格，所以Jenny根本不愿意跟他出去约会。