[He certainly catches that reaction, the discomfort inherent in it. With a hint of guilt:] We don't know anything for certain; we should try not to jump to conclusions if we can avoid it.

[Nathan doesn't want to make accusations, either. Occasional bouts of being judgemental or patronizing aside, Misa is a nice person overall and he would much rather not think ill of her. Even so:] I cannot imagine hiding it if it weren't important.