Kevin Argeneau is Kaylee Tranter’s boyfriend. Sort of. Like everything surrounding this crew, expectations and reality are somewhat fluid.
Kevin is mentioned in the Hyperion and Meagan novels, but first appears, in person, in the novelette, Expulsion, where he assists Kaylee in not having her life ruined. He’s happy to do so, although he’s a bit worried the cat Kaylee is taking care of just might want to bury him in the back yard.