Joanna: What are you doing?
Chandler: I'm getting dressed.
Joanna: Why?
Chandler: Because when I go outside naked, people throw garbage at me.
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When Rachel finds out that Ross and Julie are getting a cat, watch Rachel's neck. When she says "together?" she's not wearing a necklace; cut to Ross and Julie for a fraction of a second, then when it cuts back to Rachel saying "both of you?" she's suddenly wearing a necklace. It then disappears again when she says "isn't that just lovely?" hanging off the side of the tray she's holding.
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Matthew Perry's wit is so legendary that the scriptwriters have often incorporated his gags into the show.
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