My being American has absolutely nothing to do with it. [How does one say something like this? He almost feels sort of bad but is still a bit indignant about the whole thing.]

I'm sorry, I can't... It's much too sudden. I barely know you. I'm simply not that kind of person. Forgive me, Major, but this is the first time I've been propositioned like this and I didn't understand that that's what you wanted initially. I'm not sure what to think.