...Sorry, I can't.

This is really something that I can't tell,

Something I've gotta keep with me.

So it's that personal... The admiral used 俺 in his previous sentence which is informal and indicates that the 'matter' is a private one not related to his official duties. please change if not suitable

...Can I ask you to keep it from everyone else?

You really think I can tell them? If Fubuki's bunch heard about this they'd be all up in tears and arms,

saying, "Why are you fighting by yourself?"

Ahhhh- They would say that

But Miyuki-chan won't get angry?

Nope.

You really should...