poker-faced
adj. 没有表情的,一本正经的; 面无表情
If you are poker-faced, you have a calm expression on your face which shows none of your thoughts or feelings.
His expressions varied from poker-faced to blank...
他的表情在一本正经和茫然惶惑之间变幻不定。
The officer listened, poker-faced.
那个官员面无表情地听着。
1. deliberately impassive in manner;