Cordelia sighed, and tried her best to run faster so as to keep out of reach of the blood. Her grip on the boy tightened somewhat, though his thrashing about made it kind of difficult for her to do so. She would have to manage, though, since she didn't want the poor boy to poison himself.
"Listen, I'll make a deal with you," she told him. "That blood is old, freezing cold, won't do anything for you, and is one of the most poisonous things for us. If you stop, you can have fresh, warm blood that isn't going to harm you, and you can have as much of it as you please. Ok? So try to calm yourself and you can have something better..." She didn't know how to handle a vampire going through blood lust, especially one who could control blood himself. She would just have to try.