I also think that Gyeol is deeply flawed, but I feel like he is trying to gain control of the situation through sex. Yesung is doing the same thing, seducing Gyeol when he really put both of them in danger in doing so (not saying he is not in his right to try to escape from his situation). He felt empowered by having control over his sex life again in secret, but he realized in the prolonged sex/torture scene with the old fuck that he's been foolish and now he feels even more trapped, and try to gain this feeling of control back with Gyeol. Except now he can't feel it through sex, he barely gets reassured by tenderness and lets himself get pushed around by Gyeol (when he was extremely pro active at the beginning).
I can't fault Gyeol for not as king, because Yesung has been secretive since the beginning of their relationship. In a way, he probably feels like the most solid thing they have is sex. Which makes it very understandable why when he seeks closeness with Yesung, he gets physical, because it's how they connected at first and he wants that easyness back, but can't grasp it either. He even tries to communicate during sex, probably because only then can he feel like Yesung and him are being connected and open about something (pleasure).
Tldr : they're both looping control of the situation and try to connect through desperate sex, no one is happy, old fuck is the problem
I do enjoy this story, but omg Gyeol genuinely is so poorly written, all other characters have some sort of depth to them, but Gyeol cant even function like an adult and it isn't even anger issues he cant think straight for one chapter since the beginning, Yesung suffering and struggling so much but all that dickhead thinks of is sex.
And he wants to save yesung and obv he doesn't wanna talk about it, but not once these 40 something chapters did Gyeol sit down and ask him what's going on why how etc etc but he wants to save him?? Brother maybe have a conversation with the man instead of using your dick every time u see him privately?
I do hope this story turns out in a good way but seeing how in the raws still nothing changed I hope maybe in the end it'll have some sort of explanation