Alfie might have tried to stand up again if Goyle hadn't started talking and - fuck. FUCK! How did he know. Only his sister and his best friends knew and he knew that none of them would tell Goyle or anyone else, and ... seemed? Like he'd seen them? That was impossible wasn't it?
"I don't know what the fuck you're talking about, Goyle. Let me up!" Except it was obvious enough from his voice that he was lying, that he knew exactly what Goyle was talking about. And that having Goyle that close and in his face was making him really fucking nervous about what was coming next.