concubine
实际上,用concubine表示"小三儿"是不确切的,更准确地说,concubine是"小妾"或"妃子",杨贵妃和甄嬛都曾是concubine,这没什么拿不上台面的,制度使然.在这个意义上,concubine本身不承担道德义务,倒是某种前现代制度的牺牲品.
例句：
The Islamic State vowed to kill all the men and make concubines of the women. （Washington Post）
伊斯兰国号称要杀死所有男人,让女人为妾.
Persian King Darius III also had several wives and kept a stock of 360 royal concubines "for his own personal use."
波斯国王大流士三世有数个妻子,和360个妃子供自己享乐.
home wrecker
One who comes into your life, and screws it all up. This involves stealing your boyfriend/girlfriend, puppy, your friends, until they pretty much take over your entire life.抢走你男人的女人.
That home wrecker stole my man!!
那个女人抢走了我男人！
I am Jackie, you are Marilyn
我是正房,你是小三儿.
这个说法有点意思,Marilyn招谁惹谁了,怎么就小三儿了呢.这背后有个典故,Jackie是美国前总统肯尼迪的夫人Jacqueline Kennedy,聪明又优雅；不说也知道了,Marilyn就是Marilyn Monroe,甜美诱人的梦露,梦露就是传言中肯尼迪的小三儿,于是Jackie和Marilyn的形象也刻板化为正房和小三儿了.
hanky-panky
本意是偷鸡摸狗的小伎俩,引申为不合法的两性关系,也用来泛指男女间卿卿我我的事.
We do not allow any hanky-panky around here.
在这里,我们不允许任何胡来的事.
play the field
脚踩两只船,玩弄别人感情.可能这不违法,但没道德.一个脚踩两只船的人怎么说？Two-timer.
She's not interested in marriage at this stage, so she's quite happy to play the field.
她目前还不想结婚,所以乐得脚踩两只船.
Fling
短期的同居关系,比一夜情要长,又没有婚外情那么严肃.
It was just a fling with David... I don't expect it to go into a relationship.
我和大卫只是玩玩而已,没想跟他谈恋爱.
fornication
很正式的词,表示通奸.
The policy also mandated disciplinary action for sexual assault, incest, adultery and fornication. （Reuters）
该政策还对性侵、乱伦已经通奸等行为采取惩戒处分.
