Honestly it’s pretty well explained in the side stories. MC knows ML is fucking crazy and even asks himself why he’s still there and even thinks about how he’s probably going to die at his hand, but then he realizes that he himself is crazy too n he stays cuz basically nothing makes him feel more alive than being with him, etc. I mean he almost stabbed him with a fountain pen cuz he pretended to forget him. That’s in one of the first chapters. He impales himself with no lube while holding ML at gunpoint during the side stories. I’m also confused wdym by forgiveness? There is acceptance but I don’t remember forgiveness?
The seme is a rapist and a really bad person because he did lot’s of internal and external damage (abuse, torture) to the uke just bc he felt like it. Mostly I hated that he raped him, that it’s so normalized and the uke just “forgave” him, that isn’t even something that he chooses from free will that’s just stockholm syndrome. Really sad and disgusting.