affair/ ə'fεər /

1.noun [s] 
(matter,business) 事情

2.noun [c] 
(romance) 风流韵事

3.n pl
(matters) 事务

4.n pl
(personal concerns) 私事

to have an affair (with sb)
(和某人)发生暧昧关系
that's your/my affair
那是你/我的私事