I Gagin Hwanbulhaejuseyo!
When Jeong-In hears that his long-time crush is getting married, he ends up having a one-night stand to forget the pain of his heartbreak. But he remembers having sex with a handsome man... What's this strange pattern on his tongue? The man Hwa appears again to Jeong-In, who is confused, and makes a bombshell announcement. He says that he is a vampire and that he has imprinted on Jeong-In. But more than anything...
"You will continue to feel excited because of the imprint. So... Won't you meet me until you find a way to release it?"
(Source: Bomtoon, translated)