a flash in the pan
[俗]昙花一现

Her success as an actress in the show business was only a flash in the pan.
作为演员，在演艺界的成功只是昙花一现。她的余生默默无闻。

注解：
flash意指闪过，pan意指平底锅；a flash in the pan系指锅中一闪即逝的火花，喻指昙花一现。

get on someone’s back
[俚]对某人唠叨没完

His wife got on his back every day. Finally he left her for he couldn’t bear it.
他的妻子天天对他喋喋不休。最后，他实在无法忍受，离开了她。

注解：
get on意指骑上，back意指后背；to get on someone’s back意指骑在某人的背上，喻指对某人唠叨没完。

 swinger
[美俚]赶时髦的人；放荡不羁的人

Many swingers even pride themselves on preserving their marriages through these arrangements.
许多荒淫无度之辈以耻为荣，居然声称他们的婚姻关系维系于荡检逾闲。

That girl is not a swinger.
那个女孩可不赶时髦。

注解：
swing意指顺应时尚、潮流、风气等，也指在上荒淫无度；a swinger系指赶时髦的人，在关系上放荡不羁的人。