The One Where Ross Is Fine - S10-E2
Audio problem: When Ross is drunk and talking to Rachel, Joey and Charlie on the couch in his apartment; he begins to say "Where do you think we can go?" but his mouth does not move. (00:12:10)
The One Where Ross Is Fine - S10-E2
Audio problem: When Phoebe and Frank Jr. are talking about giving one of the triplets away, Frank makes a very loud noise but his mouth doesn't move. Making a moan this loud requires you to open your mouth. (00:12:50)
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