Lily grinned. Sure, she spent most her time trying to keep James and Sirius out of trouble, usually with poor results, but she wasn't a complete stick in the mud. "Well, I suppose that depends on what you think I'm suggesting, Potter."
If he thought she was suggesting that they infuse a little real magic in the place, then he would be absolutely correct. They didn't have any Secrecy rules to follow here and they may as well have a little fun.