单词bill and coo
na.: (鸽子)接嘴；〔比喻〕(男女间)互相接吻；亲热地抚爱[亲吻]
网络: 谈情说爱；喁喁私语；相亲相爱
It is not unusual that courting couples bill and coo in the street or on the subway, totally ignoring the presence of others.
经常有恋爱中的男女在大街上或地铁上又搂又啃，完全无视他人的存在。
We"ll leave the two young people to bill and coo together.
我们让那两个年轻人一起去谈情说爱吧。