The One Where Rachel Quits - S3-E10
Visible crew/equipment: When Monica, Ross, Chandler and Rachel are at the apartment and Rachel is suggesting how funny Chandler is, as soon as Ross says, "Sweetie, calm down it's going to be OK," a boom mic can be seen for a short period of time, at the top of the screen. (00:13:35)
Answer: The statements that she's contradicting (that it is common, it happens to every guy, and it's not a big deal), are the things that a woman commonly says to a man who is suffering from erectile difficulty, typically to assuage his bruised ego. However, most men do not believe that these statements are true, as evidenced by Chandler's outburst. He's so caught up in the proof that women are lying about it that he gives himself away.
Rooster of Doom