Shiiiiiit... Biff froze a moment, wondering what to do. Whatever it was he had to act fast, they needed an answer. An idea came, it had a one in a million chance of working and may get him in deeper shit, but right now, he just needed something to keep out of trouble.
Fully clothed, Biff dived into Jon's bed and pulled the sheets over as much of his clothes as he could. Jon had hidden the rock in what he could assume was supposed to be his "secret stash" of mostly porn magazines and similarly embarrassing things. Taking one of them, he opened to a random page and hid his face with it. Hopefully, when whoever it was entered they'd mistake Biff for Jon and get the idea that Jon was having a, ahem, private hour. Biff kept the rock in hand; he could chuck it without saying anything to send a message. Would it actually work, he wondered?