When Ross has an allergic reaction to Monica's kiwi-lime pie, Chandler and Joey are asked to baby-sit Ross's son, Ben. While using Ben to help them try to pick up girls, they accidentally leave him on a bus. Although they later locate him, they are not sure the baby is really Ben. Phoebe loses her Central Perk singing gig to a professional singer (Chrissie Hynde), and she becomes a street singer in front of the café. Lea Thompson from Caroline in the City makes an appearance, not as her character Caroline but as a woman with a gay brother interested in where Joey and Chandler adopted Ben. Also, Giovanni Ribisi, who in later episodes portrays Frank Buffay Jr., appears in this episode as a stranger who dropped a condom in Phoebe's guitar case and comes back to get it for "an emergency." The personality of this character is rather similar to Frank Jr's; though not confirmed, they are possibly the same person. Catherine Bell also appears as Robin, one of the girls in the bus.