外遇，背叛，小三，不忠用英语说劈腿那点事儿。

1)two timer劈腿,爱情不专一的人; 背着爱人

2)mistress小三

He has a mistress in Paris .
他在巴黎有个情妇。

3)commit adultery犯通姦

Will you steal and murder , commit adultery and perjury , burn incense to Baal and follow other gods you have not known .
你们偷盗，杀害，奸淫，起假誓，向巴力烧香，并随从素不认识的别神。

4)adulterer 男性的通姦者

If any man commit adultery with the wife of another , and defile his neighbour 's wife, let then: be put to death , both the adulterer and the adulteress .
若人与一有夫之妇通奸，即与邻友之妻通奸，奸夫奸妇应一律处死。

5)adulteress 女性的通姦者

If a man committed adultery with another 's wife he had to give his own wife to the husband of the adulteress .
如果一个男人强奸了别人的妻子，他必须把自己的妻子让给被强奸者的丈夫。

6)unfaithful 出轨=having committed adultery不忠

He spies on his unfaithful wife every day .
他每天都暗中监视他那不忠的妻子。

7)having an affair有外遇；

After they separated , we found out she had been having an affair with his best friend .
在他们分开之后，我们发现她早已和儿子最好的朋友有了奸情。

8)cheat背叛/偷吃；

一个人在这个世界上最好的朋友都有可能背叛他，成为他的敌人。
The best friend a man has in this world may turn against him and become his enemy .

9)step out on 不忠实；

10)cuckold与…的妻子通奸使其丈夫戴绿帽子

His wife had cuckolded him.
妻子给他戴绿帽子了。

跟离婚相关的词汇：

separate 分居

split up 分手/离婚

marital discord 婚姻不和

marital breakdown 婚姻关系的破裂

domestic violence(abuse) 家暴

extramarital affair 婚外情

adultery 通奸

divorcee 离婚者

divorce rate 离婚率

divorce proceedings 离婚诉讼

divorce settlement(agreement) 离婚协议

child support 子女扶养

spousal support 配偶赡养

alimony 赡养费

division of property 财产分割

custody 监护权

joint custody 共同监护权

ex-husband 前夫

ex-wife 前妻

remarry 再婚