The sadness deepened on his face.

Her shoulders slumped as her sadness deepened.

He squinted at his horse and felt his sadness deepen.

The sadness in his eyes deepened.

As the Christmas holidays approached, my sadness deepened.

The sadness that had plagued me in recent weeks was deepening into unshakable melancholy.

My sadness deepened as I looked around me; or more truly I felt raw and as if I'd been skinned alive.

The sadness in Blaine's eyes deepened.

You had never been able to reconcile Barry's death; the sadness only deepened over time.

The sadness deepened as he turned that helmet in his hands.