James, Leon, Andrei and open because this may get uglier
Andrei keyed in to Leon's distress when James overpowered Leon, the shift in emotions so sudden and so intense that Andrei knew something had to be terribly wrong. He apologized to Sorin and quickly escaped the ball room, not kicking up a fuss. He didn't want to alert the teachers. Swift and silent, he began running as soon as the door behind him closed.
He saw James crouching by Leon and, trying to keep the intensity of Leon's feelings at bay, feeling them try to assault him through their shared, fraught, overwhelmed connection, Andrei knew what was happening.
Within an instant, he was behind the other vampire. He grabbed James by his hair, yanking his head up, while a knee on James' back made sure the boy was weighted down. The other hand covered James' delicate face, the thumb straying close to the eye socket. "So," Andrei growled, "seems you forgot a lesson."