Jack and Doug know each other since Jack was just a teen, due to the fact that their sister and brother, had a relationship. However, we never see them interacting with each other, except in one of the last episodes of the series. Unfortunately, we don't know much about how their relationship started, but we know the two care a lot for each other, but unfortunately, Doug, who is still not mentally ready to publicly declare his homosexuality, doesn't really like being seen around with another guy, also because of the fear of not being respected as a policeman, if people around knew he's gay. After Doug says something unkind to Jack, he gets mad at him and decides to take a break. Despite everything, the love between the two is stronger, and after Douge apologizes to him, the two get back together ; almost at the end of the series, they decide to raise as a couple : Amy Lindley, the five-year-old daughter of Jack's best friend, Jen Lindley, after the girl is diagnosed with an incurable disease, due to which, she will die at the end of the series.