I've never thought about that, maybe you are right and that's why he didn't get a boner until mutch later.
oh but i think he got turned on bc soohwa(?) used sign language during one of their "sessions" y'know?
I don't think so. Byung was fucked since long before because he came back to Korea due to shit he did abroad. This is said in the latest chapter. He is naturally obsessive and feels entitled. We have yet to find out more about him (though I hate him and that's not going to change) and he circumstances in which he was adopted (because wth is the mom so chill with him being a crazy jerk).
I actually thought that was what it was since the begining LOL with the "You made me this way" flashback and the image of the broken pot, I thought "oh man, did yohan's voice made someone 'gay' before meeting soohwa and blamed him to the point he was unnedly jealous making yohan's life impossible causing the accident from his deafness?"
I'm not kidding, I really thought about it this way since then LOL
Maybe we're wrong though hahahaha
Spoiler(I think)
Oh Byung jerked off to Yohan's voice as well ╬￣皿￣)凸 , so what if, just what IF, Yohan never accepted Byung's feelings, which made Byung violent(throwback to him saying it was Yohan's fault), and that's why Yohan was so quick to jerk Soohwan off?!