I get what you mean, it seems like he resigned himself as a 'whore' after Inhun called him one, a self fulfilling prophecy if you will.
But I'm wondering if it could also be stockholm syndrome after Nakyum masturbates and thinks of Seungho instead of Inhun, even Nakyum is questioning himself. I can't really resolve the idea that he suddenly catches feelings for Seungho when all the past instances, Nakyum is terrorized with fear from interacting with Seungho, and to suddenly flip the coin from fear/anger to lust/love... Kind of made me wonder if it's a case of stockholm syndrome instead. But this is just a curiosity I'm entertaining, not yet sure if it's a fact.

Is this possibly a case of stockholm syndrome?
I think it's great that Nakyum isn't mentally and emotionally being bothered anymore, but I wish he just ups and run away and try a little bit of living in the streets selling paintings, so he can have a little more character grit, before Seungho finds him and then try to confront him with his feelings. But oh well, I'll have to wait and see.