Kate's marriage, which was first alluded to in the season one episode "Outlaws", is meant to be a contrast with her relationship with Sawyer in the realtime events – Kate and Kevin is a heartfelt and passionate relationship where Kate tries to get involved but her lifestyle ends up on making the marriage fail, whereas with Sawyer both are afraid of intimacy and connection yet still end up together.
Kate's marriage, first mentioned in season one's "Outlaws" episode, contrasts with her relationship with Sawyer in the present timeline. Kate and Kevin have a passionate but troubled marriage due to Kate's lifestyle, while Sawyer and Kate are afraid of intimacy despite their connection.