Who is Jamie and Fatso from Lila: An Inquiry Into Morals and what is their importance?

Jamie is one of Lila's oldest friends, and Fatso is his "partner in crime." Lila seeks Jamie out when she and Phaedrus dock in Manhattan. She convinces a reluctant Phaedrus that it would be good to have a second crew member. When Phaedrus meets Jamie and Fatso, he knows it is a bad idea and will never work.