This story is from another one of my favorite authors. perfect work. I love her every work!

Fan

Summary: One is a superstar, and the other is his fan. Born from same parents. Separated at the age of four. 
Kai grew up in a world where he became, a star. Jongin grew up in a world where he become kai's fan. Something happened and the two became enemies, jongin swore revenge on the idol who humiliated him when he was only trying to help him out. Humiliation came as a package as well for kai. When jongin begins taking his revenge. Things got complicated for Jongin when he starts having feelings for kai's husband oh sehun.