He chewed on his lower lip for a while, not looking at me.

She chewed on her lip and thought for a moment.

He stared up at the house, chewing on his lower lip.

The girl chewed on her bottom lip as she thought about it.

He spends most of the time trying not to chew on his lip, with little success.

She chewed on her lower lip and nodded several times.

He considered for a long moment, chewing on his lower lip.

Chewing on her lower lip, she waited for his answer.

He chewed on his lip and looked at me for a minute.

I chewed on my lip for a second, trying to think.