The saying goes: "Don't cry over spilled milk." Chanyeol, of course, would never cry. Or love. Or feel. He is apathetic and has been since a young age when something traumatic caused him to shut out his emotions in a way to keep himself sane. A coping method. 

The only emotion he allows himself is amusement. That's something he gets every day at work. No one really thinks of what it would be like to be the 'background character' in someone else's story; the waiter that has to deal with people hiding under tables because they don't want to see someone. Chanyeol is that waiter. He has made it his personal goal to make as many people's lives as complicated or embarassing as possible; of course without being caught by his boss. 

One thing Chanyeol has to deal with on an almost daily basis is famous people that think they're all that and more. When Kris, the famous film star and model, shows up at the relatively popular resturant where Chanyeol works, he is completely astounded when someone doesn't only not know who he is, but could also care less about his existance.

Add on that Chanyeol's life purpose is to make everyone elses' lives as awkward as possible, and Kris's massive ego and pride, and there's a whole lot of fun for the main character of this background story.