I think that is just what he shows to the main character because it is obvious that he is jealous when the mc gets attention from cain. I think that he actually likes the mc and he just doesn't know how to put those feelings into actions so he comes off as more of an asshat than he actually is.
Ayo, true he could be lovable but he's so toxic because he doesn't know how to show his feelings, but it will show a sad sad past to justify all of this, idk, sometimes I wish that the bottom just stayed single or go to another manwha where he can be happier
Yeah you're right. The MC deserves better and as much as I like Cain he is a bit weird sometimes, but he could hopefully be better for the MC.
I'm pretty site that what he's feeling is not love, but his pride is geting hurt because no one has never said no to him and he has some issues that makes him want to be loved