It was sweet, the way the boy nearly glowed at the praise. Derek wasn't so vain as to think that it was because the praise was from him, so much as Alcuin was so needy for it, even greedy for it, that any praise--even from Derek--would have an effect.
"Werewolves can lose control--slip--in a variety of ways. We're stronger than humans, so if Scott touches you too forcefully, hard enough to bruise...." He swallowed, because he really didn't want to think about the times that he'd bruised Stiles, even if most of them had been on purpose.
"There's other signs," he continued, hastily. "Eyes flashing. Scott's are gold. If you ever see them flash another color--like this--" he let his eyes flash bright blue, "--you need to tell my sister or me immediately. It means something's happened. Or he could partially shift."
He looked the blond up and down. "Have you seen a werewolf shift before?"