Frasier: But wait, I told Dad I was gonna stay home that night. You mustn't tell him about this.
Niles: Oh, don't worry. He'll never suspect. I told him yesterday I was going to be away for the weekend.
Frasier: Great. Perfect. But wait a minute, you knew about this yesterday?
Niles: Uh, no, but I knew about Chimps on Ice.