The hard lines of his face softened a bit.

The face was somehow different, more relaxed, the hard lines of determination softened a little.

The tight line on his mouth softened when he saw the animal.

She looked back at him, and now the line between her brows had softened.

The lines of her mouth softened into the slightest grin.

Finally, the stubborn line of his jaw softened, and he sighed.

For a moment the grave, tired lines of her face softened into a smile.

Worf did not return the smile, of course, but the lines in his face softened.

The hard lines of his face didn't soften, the eyes held no sympathy.

There were no substantial signs that China's hard line at home was softening.