The excitement of Monica and Chandler's wedding is diminished by the news that someone may be pregnant. Chandler's hopes of not embarrassing Monica on the dance floor are ruined by his slippery new shoes, and Ross' attempts to flirt with an attractive wedding guest.

Phoebe begins dating a guy who works for Monica as a sous-chef, however, they soon find themselves in an awkward position when things don't work out for neither of them. Meanwhile, Ross discovers that a co-worker of Chandler's has been calling him Toby for five years. And Joey sets Rachel up on a date with one of his co-stars, which freaks Ross out when he realizes that this guy might become a step-father of his and Rachel's baby.

Monica and Chandler decide to throw a costumed Halloween party. Meanwhile, Phoebe runs into Ursula, who's preparing to get married soon, and as a courtesy invites her and her fiancé to the party. When they finally meet, Phoebe takes an instant liking to him, but soon she discovers that he knows nothing about the "real" Ursula.

Chandler finds out that Monica had a bachelorette party with a stripper, even though they promised not to have bachelor/bachelorette parties. Monica feels bad about it, so she organizes a bachelor party including a stripper for Chandler, however, the only one excited about it seems to be Joey. Meanwhile, Rachel prepares to have dinner with her dad and tell him that she's pregnant and it doesn't go particularly well for either of the involved parties.

Ross starts to panic when Mona suggests that the two of them could send out a holiday card together, thinking that their relationship is starting to move too fast. Chandler's newly divorced boss tries to get Monica and Chandler to go out to a dinner with him, but Monica can't stand him, so Chandler steps up to cover for her. Meanwhile, Rachel's hormones start acting up due to her pregnancy, causing her to hit on almost every guy she meets.

During Valentine's Day, Chandler and Monica discover the miracle of birth by watching an extremely graphic video. Ross hides the fact that Rachel is now living with him from Mona, which only gets him into more trouble. Meanwhile, Phoebe tries to help with Joey's depression caused by his feelings for Rachel by lending him the world's happiest dog.

At Central Perk Phoebe does a reading of tea leaves which tell her that she's soon going to meet a man of her dreams. In fact, she does meet a man she keeps constantly bumping into, however, he turns out to be a bit creepy to say the least. Meanwhile, after their conversation, things between Joey and Rachel are still weird and Joey keeps finding excuses to avoid her. As a result Rachel comes up with a rather crazy problem at work to draw him into a conversation. She doesn't realize though, how far he's willing to go to help with her fake problem after their conversation is over. Also, Ross tries to retrieve his favorite shirt from Mona's, interrupted when she returns home with a date.