"Well what am I supposed to say when you tell me that you still like my brother? Why would you tell me something like that? How do you think that makes me feel?" She had every right to be offended, but so did he. Charlie didn't want to be looking over his shoulder for Percy all the time.
Charlie wasn't sure he was willing to just cool his jets and wait for Penny to decide if she still wanted to be with Percy. "What happens if he professes his undying love for you tomorrow?"