HeartBeat - Season 1 Episode 11 Ah.. I told you not to open it until 100 years.
Overview: Woohyeol and Inhae develop strange feelings towards each other after the party. Doshik, who realizes something is going on between them, tries to take them apart by letting Inhae know that Woohyeol is a vampire. However, Inhae takes Woohyeol’s side instead. In a drunken state, Haewon calls Woohyeol, and while he's on his way to drop her off, he discovers a shocking truth.