Night-blooming heartsease (слэш)

Snape swooped around the room like a giant bat, adding ingredients to some cauldrons and stirring others. Then he stopped and tapped his wand against the benchtop impatiently. "Well? What is so important that I must risk a vital brew of Animaserum by having you in the room with it?"
His tongue was so dry, he didn't know how he would ever get the words out. "Heartsease, Professor." There, that wasn't so hard. He took a deep breath. Dementors were worse, surely.