你认为他和别人有外遇吗？

Do you think he's having an ___affair with someone?

这本书讲述了一个以悲伤结局告终的漫长爱情故事。

The book is the story of a long love ___affair that has a sad ending.

她发现她丈夫有外遇。

She discovered her husband was having an ___affair.