The One With Two Parts, Part 1

Joey falls in love with Ursula, Phoebe's estranged twin sister, which strains his friendship with Phoebe. Meanwhile, Chandler is instructed to fire a sexy employee. But he ends up dating her, and tells his boss that she is mentally unstable in order to keep her sweet, whilst Ross begins to doubt his parenting skills when he attends a Lamaze class with Carol and Susan.