Ross: So why is Erica coming to visit?
Monica: Well, because we want to get to know her better and because she's never been to NY, so she wants to see all the tourist spots. You know, the Statue of Liberty, the Empire State Building...
Chandler: Oh, those places. There's always so many people and they're being corralled like cattle. And, you know, there's always some idiot who goes "Moo".
Monica: Well, if it annoys you so much, then why do you do it?