forced smile

基本解释

I was not strong enough to disagree with you and I nodded my head with a forced smile.
我不够坚强所以我没有反驳你，我只是点点头露出勉强的微笑。
Another nonverbal sign of lying is a forced smile, which generally involves only the muscles of the mouth and not the rest of the face.
另一个说谎的征兆是强挤出来的笑容，这种笑容只是调动了嘴部的肌肉而不是整个脸部的肌肉。
In a job interview, you may have experienced an interviewer’s flat affect and forced smile rather than a warm welcome that would have put you at ease.
在面试的时候，考官要求你微笑，而不是热情欢迎你的到来，让你放松。

But when you hold a pencil further back in your mouth, you are forced to smile.
FORBES: When You're Smiling