Lanzecki had his eyes and face under control; his mouth betrayed him.
"I-yes-" Talia said, and was horrified that her mouth had once again betrayed her.
Duke's mouth betrayed a very slight grin.
You promised," he reminded her, his sensual mouth betraying the hint of a sulk.
Only his mouth, boyishly vulnerable, betrayed the turmoil within.
My mouth betrayed me and the corners turned up in a tiny smile.
Reymond's eyes grew larger and larger, the more they spoke, but his mouth betrayed, not fear, but dismay.
He was trying hard to look defiant, even innocent, but his trembling mouth betrayed him.
Her mouth betrayed an unmistakable desire to wail.
My mouth cannot betray The anguish that I know.