He doesn't verbally answer, simply nodding as he avoids Sans' gaze. The kid, Susan, his brother, still to young to know the true dangers of the world, especially of worlds he didn't even know. He knows other people will think him paranoid or ridiculous for acting as though this carnival is so dangerous, but to him anything unknown was dangerous and the carnival seemed impossible to know at all.

"It's dangerous here in ways I don't understand." It's a full sentence, and it takes a lot of thought for him to even say it out loud, but he does eventually get there.

"I can't let anything happen to him."