Biff is there to see them

They both recognized the voice of the one who had called out to them. It was none other than Biff, Sarah's football playing boyfriend. "What Biff doing here?" Sarah asked in a panic. She didn't want him to see her like this! "More importantly, how did he know we were here?" Jon asked. "And not just that, he asked if we're 'home,' implying that we live here." "What? Why would I live with you?" Sarah asked. "How should I know?" Jon replied. "More importantly, what are we going to do?" It was then that they heard the sounds of someone coming upstairs, meaning that Biff was probably coming up to check the rooms, maybe even the one they were in. There fears were confirmed when they heard a knock at the door. "You guys in your room?" they heard him ask from the other side.