No, not a computer back-up or a back-up dancer, but a back-up husband. Rainbow's leader Jaekyung has a back-up man that she plans to marry if she's still single by the time she's 40-years-old. On Quiz! Sixth Sense, she and the other guests discussed "Love and Friendship." Jaekyung said, "I used to have a male friend in my neighborhood. Whenever I had problems, I would talk to him about it. One day, he confessed his feelings for me. I never thought of him as more than a friend so I turned him down at first. Then I thought maybe that that would ruin our friendship so I told him we should get married if we're both single by the time we're 40." That's quite a deal for the boy, seeing as he might get to marry Rainbow's sexy leader. If we wants to keep Jaekyung off-limits to potential suitors, he better hone his cockblocking skills.