/HERE!/
It’s no big reason or anything but it’s just such an adorable name that suits them so well. I think that was about the time when people started to really realize the amazing prowess and epicness of the ChangKyu couple (of course 21st August 2010 will forever be the most epic day ever, during SM Town when Kyuhyun dropped Changmin on stage) so people just associated ChangKyu with Caramel Macchiato since. :D

It’s unique, it’s meaningful to them, to Changmin’s tastebuds it’s a fitting description of his Kyuhyun, so why not? :DD

Their other couple-related names also include 촹규 and 88line couple (though they’re both considered 87 too and don’t have to call 1987 borns ‘hyung’) :D