Oh man, you've hit on my favorite kind of angst. The tension in these stories is almost unbearable in the best way. It's not just about loving the 'bad guy'—it's about loving someone whose entire existence is built on a code that demands emotional detachment and violence. The protagonist, usually an outsider, has to reconcile the gentle, protective person they see in private with the brutal reality of the life. The biggest struggle is the constant, gut-wrenching fear. Not just fear for their own safety, but this sickening dread that the person they love will be killed, or will have to kill, or will simply vanish one day.
There's also this profound loneliness. They can't talk to anyone about the relationship, not truly. They live in two completely separate worlds, and that isolation warps their sense of normalcy. Every mundane joy—a quiet dinner, a walk in the park—is shadowed by the knowledge of what he does. And then there's the moral conflict, which I think gets glossed over sometimes. Loving someone who commits acts you'd find abhorrent in anyone else? That’s a psychological minefield. You see them wrestle with justifying the unjustifiable, all for love. It makes for such a messy, compelling read because there's never a clean resolution, only a fraught, fragile peace.