[When Lily arrives at MacLaren's, she throws a bowl of beer nuts in Barney's face]
Lily: How did you do it?
Barney: Oh, God, you found one of the cameras. I swear that's the only one. Wait, which one did you find?
Lily: What are you talking about?
Barney: What are you talking about?
Lily: My visit to a certain Dr. Stangel.