The One With The Secret Closet - S8-E14
Continuity mistake: In the scene where Rachel comes in to have Joey feel her stomach, he gets up from the bed and you can see the boxer shorts he is wearing. You can also see them at the end of the scene, even though he is supposed to be naked. (00:03:00)
The One With The Secret Closet - S8-E14
Continuity mistake: When Chandler mentions how long Alexandra has been massaging Monica, he is holding a bowl,and he walks away with it. But when Monica says to Phoebe, "you can understand why this would be weird for me", the bowl is on the table. (00:05:20 - 00:06:00)
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