@Malice_mizer you might not need it anymore but basically the dude on the phone is minwoo, the unrequited love of Dojun (main character) who we saw at the start of the manhwa. On the phone, his step brother heard him talking about how he was just playing with Dojun, no strings attached
Recs:
Spoiler!
Checkmate, Truth or Dare, Bloodbound, Lost in the Cloud, Your Wings and Mine, Black Mirror, MadK, Fangs, Hide Mansion, One Room TA