At close range he could see that the face beneath it, despite its stern expression, was very young.

The smile died on her face at his stern expression.

They could see past the stern expression to the emotional battle going on inside.

She looked at the stern expression on the captain's face.

He was fighting back a smile behind that stern expression, she could tell.

A stern expression seemed to have frozen on her face.

Usually, a firm "no" and a stern expression are enough to control this behavior.

She smiled at him, the stern expression leaving her eyes.

Not when they were close enough for her to see their stern expressions.

He leaned into the camera, his face set in a stern expression.