In an instant, Severus watched as Hermione changed from a timid to angry.
"Bastard!" she screamed. "How the fuck could you?"
She brought her hand back and swung hard. He grabbed her wrist before she could contact with his cheek. Feeling an anger he rarely felt towards his wife, he squeezed her wrist.
"Don't you ever try to hit me!" he screamed in her face, still holding her wrist.
In another instant, she changed from angry to terrified. Tears welled in her eyes. "God, Severus, you're hurting me," she said as he twisted her wrist.
He twisted harder, feeling a satisfaction of causing her pain.