I think that makes his behavior even worse tbh. Our ml knows how it is to be in the same situation as Dan and yet he treats him like crap and doesn't show generosity /kindness like his former teacher. Instead he rapes dan, insults him, humiliates him (the scene where pink hair guy sees them fucking) and forces him to the end of the edge... Honestly, i want the ml to suffer and suffer and suffer...
i think its trauma mentality. it seems like he genuinely thinks he’s helping dan (gave him a place to stay, helped him with loan sharks and debt). i don’t think he ever really grasped the idea of consent (hell the human race barely did until recent decades) so in his head it was fair exchange, he never thought that dan was doing anything to him out of the kindness of his heart but because he helped dan, not because dan loved him or anything like that.
he doesn’t seem to be someone who’s ever self reflected inwardly his entire life, simply because he was in survival mode and if he did think about it he would probably break down. he already accepted life as take and take and it worked for him, he was validated for being ruthless, of course this only reinforced his personality.
no other previous partner probably ever treated him with such care as with dan (most seemed to be implied as consensual paid partnerships) which is why he unconsciously cares for than though it’s limited by his own beliefs.
this doesn’t excuse it or anything, but it explains his behavior. many people are like this, their personality stays this shrewd way because it “worked” for them regardless of if it destroys themselves or their relationships. some people don’t have the capacity to think deeply because it’s never been safe for them to do so and at the end of the day, all everyone’s humanity craves is safety.
holy yap lol
So he insults and belittled Dan because he sees his former self staring him in the face and he can't handle it. Doesn't excuse the behavior though.