今天要講的三個習慣用語正巧分別有one, two, three這三個數詞，而且都和浪漫情調有點關聯。它們時常被用來描述男女間的戀愛關系。

1. one and only 愛人，情人，心上人
不論男女都可以用one and only來指自己的意中人，也就是你正式選定的情人。這一習慣用語沿用至今有一百來年了。
舉個例子。說話的人要告訴我們他兄弟Bill的婚事，Bill馬上要跟自己鐘情多年的女朋友Mary結婚了。
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.
現在差不多是時候了。Bill和Mary整個高中和大學年代都相愛。好幾年來他倆一直是彼此的唯一情人。Bill從來沒注意過別的女孩，而Mary也從不跟其他男孩出去約會。

2. two-timer 愛情不專一的人；騙子
Timer原來可以指按時計算報酬的工作人員，但是用在兒女私情上就不是那個意思了。Two-timer跟有忠誠不二的含義的one and only可說是恰恰相反。Two-timer指的是那種腳踩兩只船的人。這種人三心二意同時交兩個異性朋友，而且把兩邊都蒙在鼓里，騙得那兩個人都相信自己是他/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。他原來跟Sally談戀愛已經很久了，Sally也認為Pete跟自己是認真的。后來Pete又開始和Pauline密切交往，結果Sally和Pauline都發現了實情，于是吵翻了天，兩人都再也不想見Pete這心猿意馬的人了。

3. three bricks short of a load 腦子缺根弦
Brick是磚頭，大家一定知道short of這個短語的意思是缺少什么，而load是負載量，可能是一車或者一馱，也可以是一擔、一船等等。
如今你不僅在校園里，還會在辦公地點聽到人們用three bricks short of a load來談論男女戀愛關系。這一習慣用語的意思就是腦子里少了根弦，智力不夠發達。
舉個例子。說話的人要告訴我們的是為什么他妹妹Jennie對Elmer這小伙子無動于衷：
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.
他說：Elmer長相不俗，而且彬彬有禮，穿著又得體，是個好人。但是Jenny說問題在于他一點都不聰明，學校功課剛勉強及格，所以Jenny根本不愿意跟他出去約會。