Because it's been hard for me to keep up with the different volumes on here, I'm reading it online, I'll put the synopsis.

Sangwoo has Bum at his mercy, blindfolded and naked. But Bum isn’t the only one feeling vulnerable. As Sangwoo toys with his captive lover, the story of his father’s death is revealed—and the unsettling truth behind his relationship with his mother unfolds...

Okay, the blindfold is off, Sangwoo is officially going off the rails and this is not going to end well.