He was one of the few people who could look efficient with his mouth open.

She was looking straight ahead, through the doorway, with her mouth wide open.

I looked at him, speechless, no doubt with my mouth hanging open.

She looked at him with her mouth open in surprise, but he was insistent.

She looked like a ghost, a very still one, with its mouth slightly open.

Again Jack thought that he must look rather funny with his mouth open.

I looked at him with my mouth open, and the burning boy disappeared.

The guard was looking at Brutus with his mouth open.

I looked at her in surprise, with my mouth full.

Miles no doubt looked least military of all, with his mouth gaping open in shock.