You are still wet behind the ears.

你耳朵后面的毛还湿着呢。

Stop dating her. She's still wet behind the ears.

别和她约会，她还是乳臭未干呢。

Don't rely on his advice; he's still wet behind the ears.

不要依赖于他的建议；他尚初出茅庐。

They won't let their daughter date because she's still too wet behind the ears.

他们不会让女儿去约会，因为她仍涉世不深。

Look, I want an experienced teacher, I don't want someone who is wet behind the ears.

听着，我想要一个经验丰富的老师，不想要一个乳臭未干的人。