Continuity mistake: When Joey is talking to Ross and Chandler about missing Phoebe's birthday, Chandler has the newspaper in his hands. In the next shot, you can see that Chandler does not move at all, then in the next shot, the paper is on the table. (00:04:35)Dwarf
Monica: What happened to your teeth?
Ross: I whitened them.
Ross: Yeah, what... What do you think?
Monica: Well, uh, I think I shouldn't look directly at them.
Ross: Come on, seriously.
Monica: Ross, they're really, really, really white!
Chandler: Yeah, what was wrong with your old... Human teeth?
Ross: Well, I did leave the gel on a little longer than it said to.
Monica: How much longer?
Ross: Uh, uh... A day.
Monica: Ross, you know that tonight is your date with Hillary?
Ross: I know! That's why I did it! Come on, are they really that bad?
Chandler: No. No, no, no, you'll be fine. Hilary's blind, right?
Monica: She will be after tonight.