I need help finding this Manhwa

Okay so it was about these two guys in modern time who hated each other, guy A somehow got guy B to go to his hide out house place? and guy A had given guy B a potion to give him a coinslot (I don't remember how) and later guy B wanted to get freaky so he used a bunch of pens to put up there. Guy A walked in on him since he had left earlier and just got freaky with him and that's all I remember ╥﹏╥