The gang makes--then breaks--a pact to celebrate New Year's Eve without dates. Ross compensates for his loneliness by getting a roommate, a monkey named Marcel.

Phoebe gets upset with Joey when he blows off dinner with her for a date, however only a few days later she finds herself in the same situation but with their roles reversed. Meanwhile, Chandler and Rachel enjoy a cheesecake that gets delivered to their address by accident. They feel guilt-ridden at first, but it's just too delicious. Also, Ross and Monica attend a wedding reception of their cousin and find themselves in an awkward situation.

Ross and Rachel hire a nanny for Emma named Sandy and things seem to be going great. However, Ross is uncomfortable having a male nanny. Meanwhile, Chandler becomes upset when Monica says that somebody from her new job is the funniest guy she's ever met. Also, after Phoebe and Mike decide to take their relationship to a new level and exchange apartment keys, Phoebe gets a surprise visit from her ex-boyfriend David.

When Monica and Chandler learn of their chances for natural conception, they resort to interviewing unsuspecting male candidates to find the perfect match for one who could inseminate her. Elsewhere, Phoebe is incredibly nervous about going to a party that Mike will be at--until she bumps into David. Meanwhile, Rachel finds herself being mean to Charlie because of their common romantic interest in Joey, and Ross works hard on a lecture he hopes to present at a paleontology convention in Barbados.

Chandler gives David advice that culminates in David deciding to propose to Phoebe. However, Phoebe is still in love with Mike. Monica meddles and calls Mike, who shows up in Barbados and interrupts David's marriage proposal with one of his own. Phoebe chooses Mike, although she doesn't accept his proposal. Meanwhile, sparks fly between Ross and Charlie when they spend some time together rewriting his speech.

Charlie and Joey break up, and Rachel finally tells Joey about her crush on him. He decides nothing can happen because Ross is a good friend, but after he sees Ross and Charlie kissing, he heads back up to Rachel's room where the two kiss and shut the door. Meanwhile, Monica and Mike compete at a game of ping pong.