"Why would we have? He'd have just told us not to do it and been a wet blanket," George answered. He hadn't been there for the conversation, or have Fred's slightly altered perception of events. Percy had been a stuck up, big-headed, irritatingly rule-abiding git. The twins had consistently tortured him, sure, but he'd asked for it, George thought. Mostly by being so consistently in need of loosening up. It had been a public service on their part.
If they'd have tried to get Percy out to do anything fun, he'd just have docked points. Or told mum or something.