Kim Seokjin and Kim Namjoon (Jin and Joon to each other, among other pet names) have been together for a long time, and are as good as married. In fact, they're just your basic old married couple. Doesn't mean their love life has taken a dive, or that they are any less grossly in love with each other, or any more gross in their lovemaking. ("Joon-ah, are you talking romantic again?")