Percy wanted to say no on principle, just to watch that smirk disappear, because sometimes it really did remind him of the twins and that was never a good thing. However, he was also aware that saying no would deprive him of sex as well.
"I wasn't serious about owling him," he said. He turned toward Cass and touched his face, fingers moving gently over Cass' cheeks and lips. "I guess we could go to bed and nap, and if after you walk upstairs, you still want to- We're going to have to trust your body; I am going to have to trust you to tell me when it's too much. Don't do anything stupid, Cass. Please."