Precious was Mike Hannigan's girlfriend for three months during his break with Phoebe. When Monica called Mike about David's plans to propose to Phoebe, Mike left for Barbados without telling Precious. When he returned, now in a relationship with Phoebe again, he completely forgot about Precious. He had made plans for a date with her, and now decides he will break up with her on that date.
Because of some confusion, Mike thinks they were supposed to meet at a restaurant and Precious thinks they were supposed to meet at Mike's. When Precious arrives, she finds Phoebe, who is forced to tell Precious everything. She gets very upset and Phoebe tells her lots of good things about her and bad things about Mike to make her feel good about herself. When Mike finally gets to his apartment, Precious tells him off, slaps him on the face, and storms out. All of this occurred on Precious' birthday.
Phoebe made fun of Precious' name by 'asking' if she was a dog. Ironically, when she turned up, her posture and behaviour was similar to that of a dog.