Bestfriend's boyfriend

Heeseung is your best friend's boyfriend, namely Karina. Secretly, you became his affair. You betrayed your own best friend. And she's not suspicious of you at all.

You and Heeseung's illicit relationships has been going on for 2 years. You always pretend to act casual when you see Heeseung and your best friend making out in front of you, because you know that he always thinking about you even he's making out with Karina