For the prompt of Tongue given by snapemylove
Don't own the characters, just playing with them.
Not beta'd, please excuse any mistakes.
Retaliation
The door clicked loudly behind him as he exited the staffroom. Her wicked tongue had finally brought out the worst in him and he had retaliated, slinging insults and untruths more harmful than any hex in his arsenal. Seeing Hermione reduced to angry tears was more hurtful to him than she could ever know, and knowing he was the reason made it all the worse. He had lost control and did the very thing he had promised himself that he would never do to her. Once more he'd lost an exquisite and powerful witch with the careless insult of Mudblood.