嬉皮笑脸

They are grave or impertinent all the day long.

他们这一天里不是庄严肃穆就是嬉皮笑脸。

Don´t trifle with me.

别跟我嬉皮笑脸的。

You should be serious in class. Don´t behave in a noisy , gay , and boisterous manner.

你上课要严肃， 不准嬉皮笑脸。

He was indeed a thoughtless, giddy youth, with little sobriety in his manners incountenance.

他确实是个轻率 、 浮躁的少年， 举止随便，嬉皮笑脸。

We are like a group of army deserters, Xipixiaolian day, and sometimes instructors let us laugh.

我们就像一群逃兵， 整天嬉皮笑脸， 有时教官也让我们逗笑了。