Ah, I see what you mean, and I think most of our differences lie from what it means to "use" someone, mainly that I think you can use someone without the intent to hurt.
And I agree that Nunnally getting in the know is the far more honest option. However, if we were to look at the boys in season one ("one" being the operative word), they are anything but fully honest to her. Lelouch lies to her all the time (or at least tells half-truths), and Suzaku never really delves into the serious bits of his life with Nunnally around. They have had a history of sheltering her for her own best interest, because if she was cognizant of everything, she would surely try to do something about it. And Nunnally taking an active role is undesirable for two reasons: 1) her motivations put a leash on the boys and their ambitions, and 2) she would presumably put herself in the spotlight and/or in harm's way. And I still think that that realization would be cruel, at least from the boys' perspective, because an ignorant Nunnally has infinite choices, while a knowing, empathetic, and empowered Nunnally only really has one. It's a drastic reduction in freedom and increase in moral burden.
So (in my mind), for Suzaku there's competing claims of utilitarianism and keeping Nunnally out of this mess. The caveats are that he may have no control over the latter, and even if he does, R2!Suzaku is different and perhaps a character I dislike more from a purely subjective standpoint.
Re: too long, as usual
And I agree that Nunnally getting in the know is the far more honest option. However, if we were to look at the boys in season one ("one" being the operative word), they are anything but fully honest to her. Lelouch lies to her all the time (or at least tells half-truths), and Suzaku never really delves into the serious bits of his life with Nunnally around. They have had a history of sheltering her for her own best interest, because if she was cognizant of everything, she would surely try to do something about it. And Nunnally taking an active role is undesirable for two reasons: 1) her motivations put a leash on the boys and their ambitions, and 2) she would presumably put herself in the spotlight and/or in harm's way. And I still think that that realization would be cruel, at least from the boys' perspective, because an ignorant Nunnally has infinite choices, while a knowing, empathetic, and empowered Nunnally only really has one. It's a drastic reduction in freedom and increase in moral burden.
So (in my mind), for Suzaku there's competing claims of utilitarianism and keeping Nunnally out of this mess. The caveats are that he may have no control over the latter, and even if he does, R2!Suzaku is different and perhaps a character I dislike more from a purely subjective standpoint.