Billy just arrived at Byer's, he somehow found out his (and your) sister, Max, was there. Steve tried to stop him, telling him Max wasn't there, but he saw her inside the house, pushed Steve and entered, he aggressively pinned Lucas against a wall, you shouted for him to stop until Steve entered the house back and punched Billy across the face.

"Leave."

Steve said, cold and aggressive, Billy just laughed.

Billy: Well I was waiting forward to seeing who this so called "King Steve" was...