"Biff?" Jon hesitantly asked.
Biff yawned, then opened his eyes. "What the hell? What are you doing in my bedroom?! What are you doing in my house?!"
"This is my house," Jon said.
Biff's eyes drifted down at the bed. He did notice that it wasn't his bed, but that wasn't the first thing he noticed. He saw that the left side of the covers had been pulled back, meaning someone was in bed with him. And his eyes filled with horror, as he realized that that person was Jon.
"You sick fuck," Biff said. "Did you sleep with me?" He felt under the covers and his face filled with even more horror, as he realized that he was naked.
"I didn't sleep with you. Or anyone. I woke up just a minute ago and found you in my bed. Believe me. I'm just as disgusted by this as you are."
"I think I'm more disgusted than you think." Biff looked around the room for his clothes, but they didn't seem to be there. "I can't remember how I got here."
"And I don't remember you coming."
Biff glared at Jon for a moment.
"I didn't mean it like that," Jon said. "Listen, nothing happened. I just woke up and you were here." It was at this time that Jon started to wonder if this strange turn of events had anything to do with his vague wish for something interesting to happen. He wouldn't exactly call this "interesting", though. Maybe "strange" or even "sick". But he didn't want to tell Biff about the wishing stone. So he decided to act completely baffled by what was happening. He could always make a wish later to erase Biff's memories of this.
"You better hope nothing happened. Because if something did ..."
"I promise. Nothing happened."
Biff scanned the room again, but still couldn't find his clothes. He groaned, then said "I need some of your clothes." He really didn't want to wear this loser's clothing, but he couldn't just walk around naked.