cut in line 排队时插队

I get annoyed when people cut in line.
一有人夹三，我就心烦。

tell on people 打别人小报告

He often tells on his classmates.
他经常告同学的状。

stand people up 放别人鸽子

I've been stood up!
我被人放鸽子了！

stab someone in the back 暗中陷害别人

He will say nice things to your face and then stab you in the back.
他当面说得好听，背后会给你使绊儿。

swear all the time 一直说脏话

It's wrong to swear and shout.
骂人和喊叫是不对的。

break your promise 违背诺言

How could you break your promise?
你怎么不守信用？

have an affair 搞婚外情

I felt bad for Joan when Jack started to have an affair last year.
杰克去年开始在外面有外遇。 我为琼感到很难受。

be ungrateful 忘恩负义

After all I had done, she was still ungrateful.
尽管我做了这一切，可她仍然不领情。

rat people out 出卖别人

Where I come from, you don't rat on your friends.
在我的老家，谁都不出卖朋友。