Kylie dated J.D. for a short while.
J.D. meets Kylie at the nightclub where she works, but is disappointed to find that she has a boyfriend, whom she later dumps when she learns he had contracted an STD while cheating on her (the two had not slept together). ("My Hypocritical Oath")
J.D. and Kylie's first date is complicated when they get stuck in a SARS quarantine at the hospital. Trying to show off to her, J.D. pays a homeless man to fake a heart attack so he could save him. Not wanting to lie to Kylie like her ex-boyfriend used to do, he tells her the truth, but she manages to forgive him. ("My Quarantine")
As a result of their busy schedules, they have to maintain their relationship with "appointment kisses." Kylie's refusal to sleep with J.D. drives him crazy, to the point that he almost cheats on her with Molly. When J.D. tells her actually meaning well, Kylie breaks up with him ironically just before they almost finally sleep together. ("My Best Laid Plans")